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A COURSE 



Home Study for Pharmacists 



FIRST LESSONS 



STUDY OF PHARMACY 



OSCAR OLDBERG, P. D., 

Professor of Pharmacy and Director of the Pharmaceutical Laboratories in the Depart- 
ment of Pharmacy of Northwestern University (Illinois College of Phar- 
macy) ; Member of the Committee of Revision and Publication 
of the Phafmacopceia of the United States. 



WITH 150 ILLUSTRATIONS. 



2^/3 



U W 



CHICAGO: 

PUBLISHED BY THE APOTHECARIES' COMPANY. 



«3\ 



ftS 



Entered according to Act of Congress, in the year 1891, by 
OSCAR OLDBERG, 

In the Office of the Librarian of Congress, at Washington. 



ALL RIGHTS RESERVED. 



DONOHUE & HENNEBERRY, 

PRINTERS AND BINDERS, 

CHICAGO. 



PREFACE 



Out of at least 75,000 persons employed in the drug stores 
of the United States only a few thousand have enjoyed the 
advantages of systematic courses of special education offered by 
the colleges of pharmacy. But many thousands who can not, or 
think they can not, attend a college of pharmacy devote a por- 
tion of their time at home or in the store to such studies as they 
may think most useful to them in their professional work. 
Others, again, whose purpose it is to enter a college of phar- 
macy at the earliest opportunity, lind it highly advantageous to 
employ whatever time is at their disposal in suitable preliminary 
reading in order to so prepare themselves for the college course 
as to be able to derive the greatest benefit from it. The phar- 
macy laws, too, oblige many thousands to study at least enough 
to pass the State Board examinations. 

But whatever may be the motive that impels the prospective 
pharmacist to study, the measure of success he attains will 
depend upon what and how he studies. The book he reads 
must be that best adapted to his previous general and special 
education, and a text-book which may be unsurpassed when 
studied with the guidance and help of a teacher may be quite 
unsuitable for home study. 

Whether the road to the acquisition of knowledge be good, 
bad or indifferent, the student must travel it himself; no one 
else can do it for him. But the choice of a route is of scarcely 
less importance than the untiring pursuit of it. 

The best way to acquire a pharmaceutical education is to 
attend a good college of pharmacy No course of study at 
home can take the place of a good college with its experienced 
teachers and its invaluble laboratory practice; but home study 



Vi PREFACE. 

is of the highest importance to those who are prevented by cir- 
cumstances from entering college. 

The author has for several years past been called upon 
almost daily to recommend to prospective students of pharmacy 
some plan for systematic home study. Those who have asked 
such ad-vice were as a rule young men of fair common school 
education, but having little or no knowledge of physics, chemis- 
try, botany, or materia medica, or of the application of these 
branches of science to pharmacy. 

This book is the result of the author's effort to help his 
friends who thus call upon him. It is prepared expressly for 
prospective pharmacists and, therefore, adapted to their special 
wants 

It is a book of — 

FIRST LESSONS 

IN THE 

STUDY OF PHARMACY, 
and the Author has endeavored to treat the subject matter in a 
manner which will enable his readers to acquire a good knowl- 
edge of the essentials, and to utilize their opportunities of 
observation in the drug stores to facilitate their progress. 

The scope of the book is indicated in the table of contents. 

Throughout the book there are many cross-references to help 
the student. At the same time the author has not hesitated to 
repeat wherever repetition seemed likely to be more convenient 
to the reader than to refer him to other portions of the book. 

While Part I covers the whole field of Physics, only such 
portions as have a special interest to the student of pharmacy- 
are treated at any length. 

Part II covers theoretical chemistry quite sufficiently, and 
the experiments and examples given are such as the drug store 
affords. Chemical formulas, which are nearly always difficult 
to beginners, have been printed in two colors in the ten chap- 
ters devoted to the different classes of chemical compounds — 
the positive radical of the molecule in black, and the negative 
in red, so that the student can identify each at a glance. 



PREFACE. Vll 

Part III presents definitions of such general terms as medi- 
cines, drugs, chemicals, preparations, materia medica, pharma- 
cology, pharmacognosy, pharmacy, pharmacopoeia, pharmaco- 
dynamics, therapeutics, posology, etc. Chapter LXIII is devoted 
to a general review of the various classes of chemical constit- 
uents existing in plant drugs. 

In studying of the chemicals in Part II and of the crude 
drugs in Part III, the student should familiarize himself with 
their appearance as found in the store, and compare the descrip- 
tions given in the book with the articles described. A cabinet 
of such drugs as are not always found in drugstores except in a 
comminuted condition, will be found useful to the student. 

The symptoms of poisoning and customary antidotes are 
given under poisonous drugs. 

As the author believes that every drug clerk ought to have at 
least some idea of what is meant by such common therapeutic 
terms as alteratives, antipyretics, hypnotics, carminatives, dia- 
phoretics, etc., definitions of terms of this kind are given in 
Chapter LXXIV. 

The Dose Table which constitutes Chapter LXXV is a most 
extensive one, covering nearly 1,000 articles, and includes the 
new remedies, such as antipyrin, acetanilid, phenacetin, chloral- 
amid, urethan, hypnone, the rarer alkaloids, etc. 

The author is indebted to many of the standard text-books 
on physics, chemistry, materia medica and pharmacy — foreign 
and American — for his materials. 

To the student I wish to say that the mere memorization of 
facts and theories, however valuable these may be when prop- 
erly used, should by no means be your main object. It should 
be your constant aim to clearly imder stand what you read, to 
develop your faculties of observation and reasoning, and to be 
able to rightly use what you learn. Only by using it and 
adding to it can you make it your own. 

THE AUTHOR. 

Chicago, June, 1891. 



TABLE OF CONTENTS. 

PAGES. 

Preface v-vii 

PART I. 

ELEMENTS OF PHARMACEUTICAL PHYSICS. 

CHAPTER I. 

Matter — Definition — Properties i- 8 

CHAPTER II. 
Forces and Phenomena — Attraction and Repulsion — Gravitation — 

Weight — Specific Weight — Cohesion — Adhesion — Atomic Attraction. 8- 14 
CHAPTER III. 
Phenomena Dependent upon Cohesion — States of Aggregation — Solids 

— Liquids — Gases — Fluids — Vapors - 14-18 

CHAPTER IV. 
Crystalline Bodies — Crystals — Crystallizable Substances — Amorphous 

Substances 18- 21 

CHAPTER V. 
How Crystals are formed — Axes — Faces — Edges — Angles — Cleavage — 

Cubes — Prisms — Pyramids — How Crystals are Produced 22- 25 

CHAPTER VI. 

Water of Crystallization— Anhydrous and Hydrous Crystals 25- 28 

CHAPTER VII.' 

Classification of Crystals — Crystallography — The Six Systems 2S- 35 

CFMPTER VIII. 

Adhesion — Adhesiveness — Mixtures — Miscibility 35- 37 

CHAPTER IX. 
Capillarity and Osmosis — Capillary attraction — Diffusion of liquids — 

Osmosis — Dialvsis 37- 43 

CHAPTER X. 

Solution — Solubility — Simple and Chemical Solution — Solvents 44- 47 

CHAPTER XI. 
Motion — Laws of Motion — Momentum — Center of Gravity — Equilibrium 

— Stability — Velocity — Pendulum — Energy 47- 53 

CHAPTER XII. 
Work and Machines — Units of Work — Levers — Balance — Pulleys — 

Inclined Plane— Wedge— Screw — Friction 54- 58 

CHAPTER XIII. 
Hydrodynamics— Pressure upon Liquids— Hydraulic Press — Law of 

Archimedes — Hydrometers 58- 66 

ix 



X CONTENTS. 

CHAPTER XIV. 
Pneumatics — Tension of Gases — Mariotte's Law — Atmospheric Pressure 

— Barometer — Siphon 66- 73 

CHAPTER XV. 
Heat — Definition — Active and Latent Heat — Temperature — Sources.. 73- 76 

CHAPTER XVI. 

Thermometry — Mercurial Thermometers — Other Thermometers 77- 79 

CHAPTER XVII. 
Absolute and Specific Heat — Absolute Temperature — Thermal Units 80- 82 

CHAPTER XVIII. 
Distribution of Heat — Conduction— Connection — Ventilation — Radiation 

— Transmission — Absorption 82- 86 

CHAPTER XIX. 
Expansion of Bodies by Heat — Force of Expansion and Contraction — 

Coefficients of Expansion — Expansion of Water 86- 89 

CHAPTER XX. 
Relation of Temperature to the three states of Aggregation — Action 
of Heat on Solids — Fusion — Sublimation — Fixed and Volatile Sub- 
stances — Evaporation — Boiling — Distillation 90- 97 

CHAPTER XXI 

Temperature and Humidity of the Air 97- 98 

CHAPTER XXII 
Light — Transparent, Translucent and Opaque Bodies — Luminous Rays 

— Sources of Light — White Light — The Prismatic Colors 98-102 

CHAPTER XXIII. 
Electricity — Static and Galvanic Electricity — Magnetism — Induction — 

Currents— Chemical Effects 102-106 

PART II. 

ELEMENTS OF CHEMISTRY. 

CHAPTER XXIV. 

Masses, Molecules and Atoms — Introductory — Mixed Matter — Single 

Substances — Atoms — Molecules — Masses — Elements — Compounds — 

— Physical and Chemical Properties — Physics and Chemistry. . . .109-118 

CHAPTER XXV. 

Chemical Phenomena — Relative Stability of Molecules — Reactions. . .118-123 

CHAPTER XXVI. 
Chemism — Intensity, Quality and Quantity — Factors and Products of 
Chemical Reactions — Synthesis and Analysis — Decomposition — Con- 
ditions favorable to Chemical Reaction — Relation of Heat to Chem- 
ism — Electricity — Status Nascendi — Dry and Wet Processes — Pre- 
disposing Affinity 123-131 

CHAPTER XXVII. 
The Law of Opposites in Chemistry — Acids and Alkalies — Electrolysis 

and Electro-chemical Theory — Electro-Chemical Series 131-138 



CONTENTS. Xi. 

CHAPTER XXVIII. 
Fixed Combining Proportions and the Atomic Theory— Atomic Weights 
— Dalton's Law — Law of Dulong and Petit — Specific and Atomic 
Heat — Molecular Heat — Gay-Lussac's Law of Simple Combining 

Proportions by Volume — Avogadro's Law 139-149 

CHAPTER XXIX. 
Valence — Artiads and Perissads— Bonds — Variable Valence. . . ... .150-158 

CHAPTER XXX. 

Chemical Notation — Symbols — Formulas — Chemical Equations 15S-163 

CHAPTER XXXI. 

The Elements — General Review 163-170 

CHAPTER XXXII. 

Oxygen, Hydrogen and Sulphur 171-179 

CHAPTER XXXIII. 
The Halogens — Chlorine — Bromine — Iodine 179-1S2 

:hapter xxxiv. 

The Nitrogen Group and Boron 182-190 

CHAPTER XXXV. 

The Carbon Group . . 191-195 

CHAPTER XXXVI. 

Summary of Non-Metallic Elements 195 

CHAPTER XXXVII. 

The Light Met als and Ammonium 196-204. 

CHAPTER XXXVIII. 

The Heavy Metals 204-21 1 

CHAPTER XXXIX. 

Summary of Metallic Elements 211-213 

CHAPTER XL. 

Compound Radicals — Negative and Positive Radicals 213-220 

CHAPTER XLI. 
Tables of Radicals, Simple and Compound — Positive and Negative. . . 220-223 

CHAPTER XLII 
Compound Molecules — Atomicity of Molecules — Direct Union — Chains — 

Linkage — Molecular Formulas 224-234 

CHAPTER XLIII. 

Classes of Compounds— Inorganic — Organic 234-235 

CHAPTER XLIV 

Oxides and Sulphides 235-239 

CHAPTER XLV. 

Haloids — Chlorites — Bromides — Iodides — Cyanides 240-247 

CHAPTER XLVL 

Bases — Hydroxides — Base-residues 247-250 

CHAPTER XLVII. 
Acids — Hydroxyl Acids — Hydrogen Acids — Reactions between Bases 

and Acids — Action of Acids on Metals 250-255 



XI 1 CONTENTS. 

CHAPTER XLVIII. 
Salts — Normal and Acid Salts — Basic Salts — Oxy-salts and Haloids. .256-259 

CHAPTER XLIX. 

Nitrates Chlorates and Hypochlorites 259-26 

CHAPTER L. 

Sulphates and Sulphites — Thiosulphates ... 262-265 

CHAPTER LI. 
Phosphates — Ortho-, Meta-, and Pyro-Phosphates — Hypophosphites 265-268 

CHAPTER LII. 

Carbonates — Borates — Silicates — Arsenates — Arsenites 261-270 

CHAPTER LIII. 
Metallic Salts with the Organic Acids — Acetates — Valerates — Lactates 

— Oleates — Oxalates — Tartrates — Citrates — Salicylates, etc 271-276 

CHAPTER LIV. 
Hydrocarbons — Methane Series — Other Series — Hydrocarbon Radicals 276 280 

CHAPTER LV. 
Other Organic Compounds — Alcohols — Aldehyds — Ketones — Acids — 

Ethers — Ethereal Salts — Carbohydrates — Glucosides — Alkaloids . . 2S0-289 
CHAPTER LVI. 

Chemical Nomenclature — Rules — Terminal syllables— Prefixes 289-295 

CHAPTER LVII. 
Laws Governing the Direction and Completeness of Chemical Reac- 
tions — Laws of Malaguti and Berthollet 296-300 

CHAPTER LVIII. 
Oxidation and Reduction — Combustion — Oxidizing Agents — Reducing 

Agents 301-302 

CHAPTER LIX. 
Neutralization and Saturation— Test-papers — Solution of Metals in 

Acids 303-306 

CHAPTER LX. 
Precipitation — Insoluble Compounds 306-313 

PART III. 

MATERIA MEDICA. 

CHAPTER LXI. 

Introductory — Definitions of Drugs and Preparations — Materia Medica, 

Pharmacology, Pharmacognosy — Official and Officinal Medicines — 

Pharmacopoeias — Pharmacy and Pharmacodynamics — Therapeutics 

and Posology 31 7-328 

CHAPTER LXII. 

Plant Drugs — Collection, Cleaning, Garbling, Drying 328-332 

CHAPTER LXIII. 
What Plant Drugs Contain— Proximate Principles — Cellulose — Starch — 
Gum— Pectin — Sugar— Albuminoids — Fixed Oils — Organic Acids — 
Volatile Oils— Resins — Balsams — Oleoresins — Gum-Resins — Neutral 
Principles — Tannin— Glucosides — Alkaloids 332-345 



contexts. xiii 

CHAPTER LXIV. 
Roots, Rhizomes, Conns and Bulbs 345-354 

CHAPTER LXV. 
Woods Barks and Nutgall 354-359 

CHAPTER LXVI. 
Herbs, Flowers and Leaves 360-367 

CHAPTER LXVII. 

Fruits and Seeds 367-373 

CHAPTER LXVIII. 
Miscellaneous Crude Plant Drugs 374-377 

CHAPTER LXIX. 

Starches, Gums and Saccharine Drugs 378-379 

CHAPTER LXX. 
Gum-Resins, Resins and Oleo-resins . . 379-3S4 

CHAPTER LXXI. 
Fats and Fixed Oils 3S5-386 

CHAPTER LXXII. 

Volatile Oils and Camphors 387-391 

CHAPTER LXXIII. 
Animal Drugs 391-392 

CHAPTER LXXIV. 
Therapeutic Classification of Medicines — Definitions 392-39S 

CHAPTER LXXV. 
Dose Table of nearly 1,000 articles, including new medicines 399-418 

PART IV. 

PHARMACY. 
CHAPTER LXXVI. 
Heating Apparatus — Fuel-Generation and Applications of Heat A or Phar- 
maceutical Purposes — Sand-bath, Water-bath, and other Baths — Dry 

D rocesses requiring Heat 421-430 

CHAPTER LXXVII. 
Comminution — Apparatus and Implements — Mills — Mortars and Pestles 

— Contusion — Trituration — Powders — Sifting 430-437 

CHAPTER LXXVIII 
Solution in Pharmacy — How made — Solvents — Saturated and Super- 
saturated Solutions — Partial Solution — Menstrua 437-443 

CHAPTER LXXIX. 
Filtration and other Methods of Clarifying Liquids — Filters — Filter fun- 
nels — Colation — Decantation — Clarification — Sediments 443-450 

CHAPTER LXXX. 
Evaporation and Distillation — Ebullition — Boiling vessels — Evaporat- 
ing vessels — Stills — Retorts — Condensers — Receivers — Fractional 
Distillation — Generation and Solution of Gases — Woulf's bottles.. 45 1-460 



XIV CONTEXTS. 

CHAPTER LXXXI. 
Crystallization and Precipitation — Crystallizers — Size of Crystals — 
Retarded crystallization — Mother-liquor — Granulation — Precipitation 

— Precipitating vessels 460-466 

CHAPTER LXXXII. 
Methods of Extraction of Soluble Matters from Plant Drugs — 
Extracts and Extractive — Apotheme — Maceration — Digestion — Infu- 
sion— Coction — Displacement — Percolation — Percolators 467-475 

CHAPTER LXXXIII. 
Pharmaceutical Preparations — General Review — Pharmacy of Inorganic 

and Organic Drugs Compared 476-477 

CHAPTER LXXXIV. 
Dry and semi-solid preparations for Internal Use not made by Extrac- 
tion — Species — Powders — Confections — Masses — Troches — Pills.. 477-479 
CHAPTER LXXXV. 
Liquid Preparations not made by Extraction — Solutions — Waters — 

Mucilages — Glycerites — Syrups — Spirits 4S0-4S3 

CHAPTER LXXXVI. 
Liquid Preparations made by Extraction — Infusions — Decoctions — 

Vinegars — Tinctures — Wines — Fluid Extracts 4S4-4S7 

CHAPTER LXXXVII. 
Solid Preparations for Internal Use made by Extraction — Extracts — 

Abstracts — Oleoresins — Resins 487-490 

CHAPTER LXXXVIII. 
Preparations for External Use— Ointments — Cerates— Plasters — Oleates 

— Suppositories — Gargles — Lotions — Injections — Collodions — Lini- 
ments 490-494 

CHAPTER LXXXIX. 
The Latinity of Pharmaceutical Nomenclature — Latin Declensions — 

Nouns, Adjectives and Numerals 494-502 

CHAPTER XC 
Weights and Measures — The Metric System — Apothecaries' Weights 

and Measures — Avoirdupois Weight — Equivalents 503-505 

Index 507 



PART I. 



PHYSICS. 



PART I. 



PHYSICS, 

CHAPTER I. 

MATTER. 

1. Physical Bodies are the things of external Nature which 
consist of matter (3). 

Any portion of matter perceptible to our bodily senses is a 
body. 

A body is an aggregation of any number of molecules (16 
and 17). 

We can also say that a body is any mass of matter without 
reference to quantity. 

Ex. — Any piece of wood, stone or coal, any quantity of water, air or oil, 
a lump of sugar, a crystal of salt, any animal or plant, the paper upon which 
this book is printed, the printer's ink used in it, and the book itself as a mate- 
rial thing — all these are bodies. 

[The term " body " is also often used in the same sense as the term " sub- 
stance " (18); thus we find carbon described as a "fixed body" (83), while 
iodine is referred to as a " volatile body " (83). On the other hand, the term 
" mass " is commonly employed to designate an aggregation of any number of 
molecules (16) without regard to quantity. This use of the term mass is very 
convenient, but conflicts with the universal use of that term as defined in para- 
graph 7. In this book the term body will be used only to designate any body 
of matter without regard to the actual qttantity (mass) of matter contained in 
it; and the term mass will be used in the sense fixed by its definition in par. 7.] 

2. Mathematical Bodies represent form and extension, inclosing empty 
space, thus differing radically from physical bodies which contain or consist of 
matter (3). 

We can think of and represent mathematical bodies, such as cubes, 
spheres, cones, cylinders, etc., without any reference to matter, because they 
have definite bounds although void of matter. 



2 PHYSICS. 

3. Matter is that which occupies space or possesses exten- 
sion. By matter we also understand that which possesses 
weight (40) without regard to the amount of space which it occu- 
pies. 

4. Whatever occupies space is matter, and nothing can be 
matter which does not occupy space. 

5. No two bodies can occupy the same space at the same 
time, for every particle of matter occupies its own space, to the 
•exclusion of every other particle of matter, 

This property of matter is called Impenetrability (26). 

Ex. — An egg can not be put in a tumbler previously filled with water 
without causing the water to overflow, because the egg necessarily displaces 
its own volume of water from the space occupied by it. 

Air is matter. It, therefore, occupies space. When we speak of an 
" empty " bottle and an " empty " tumbler, and say that there is " nothing " 
in them, we ignore the fact that they contain air. Experimentally, you may 
prove this by inverting the tumbler and pressing it downward in water; if 
there were nothing in it, the water would fill it, but the water will not fill it 
because the air in the tumbler occupies the space and the water can not occupy 
it at the same time. 

6. Since by Matter we also understand the weighable with- 
out regard to its extension, it follows that whatever has weight 
(40) is matter, and that whatever has no weight can not be mat- 
ter. 

7. Mass. — Any amount of matter, regardless of the space it 
occupies, is called Mass, 

Since matter is that which is weighable, its mass is ordinarily 
measured by weight (40). 

[But the mass of a particular body is a positive quantity, while its weight 
varies with its distance from the earth's surface (38).] 

The Mass of a body, then, is the actual quantity of matter con- 
tained in that body, and mass has nothing to do with size or bulk. 

8. All material bodies have volume (9) and weight, as indi- 
cated in paragraphs 4 and 6. 

9. Volume. — The volume of a body is the space occupied 
by it. 

All bodies have extension in all directions, and the measure of 
this extension is called volume. 



PHYSICS. 3 

Thus the length, breadth and thickness of a cubical crystal 
(130) indicate its extension and determine its volume. 
Space devoid of matter is called vacuum. 

10. The relation of mass to volume is called Density. 
Density expresses the relative amount of matter contained in 

a given volume. 

It is evident that bodies having the same volume may nevertheless have 
different masses, and that bodies having the same mass may have different 
volumes. Hence the necessity of the term " density " to express the relation 
of the mass (7) to the volume (9). 

11. Of two bodies having the same volume but not the same 
mass, the one containing the greater amount of matter, or hav- 
ing the greater mass (7), has, therefore, the greater density (10). 

In other words, the greater the quantity of matter contained 
in a given volume of a body, the greater will be the density of 
that body. 

Ex. — Brass and bees-wax are bodies. Let us compare equal volumes of 
these bodies. A cul5ic inch of brass contains a greater amount of matter, or 
has a greater mass, than a cubic inch of wax; the density of brass is, there- 
fore, greater than the density of wax. 

Since matter is that which has weight (3) and mass is accordingly meas- 
urable by weight (7), a cubic inch of brass must weigh more than a cubic inch 
of wax if the brass is denser. Verify this by placing a piece of brass on one 
pan of the balance, and a piece of wax of the same size on the opposite pan; 
you will find that the pan loaded with the brass piece goes down, and the 
other up. If you now add as much wax to that already placed on the pan as 
may be necessary to counterbalance the brass, the bulk of the wax will be 
several times as great as that of the brass when their weight is equal. 

12. Of two bodies having the same mass, each containing 
an equal amount of matter, but not of the same volume, the one 
having the smaller volume has, therefore, of necessity the 
greater density. 

Ex. — A pound of lead and a pound of lard have the same mass, because 
they have the same weight (40), but the pound of lead occupies much less 
space (or has a less volume) than the pound of lard; therefore, the density of 
lead is greater than the density of lard. 

13. When two or more bodies are of like density, their rela- 
tive masses correspond to their relative volumes. 



4 PHYSICS. 

Ex. — Castor Oil and Copaiba have the same density; therefore, it follows 
that one pound of castor oil has the same volume as one pound of copaiba; 
it also follows, that if one bottleful of castor oil weighs three times as much 
as another bottleful of copaiba, the bottle containing the castor oil must have 
three times the capacity of the one containing the copaiba, and the volume of 
the oil must be three times as great as the volume of the copaiba; and six- 
teen pints of copaiba must weigh sixteen times as much as one pint of cas- 
tor oil. 

14. Having now learnt what is meant by each of the terms 
body (1), matter (3), mass (7), volume (9), and density (10), let 
us next consider some of the general properties of matter (or the 
" universal properties of matter "). 

We have already seen (3) that all matter occupies space 
and has weight. But volume and weight are not properties of 
matter, for we can think of space without reference to matter, 
and weight is an effect produced upon matter by a cause exter- 
nal to and distinct from it (40). 

One of the "general properties of matter " # has been noted, 
however, namely its impenetrability (5). 

As we will presently find (17) there are very numerous forms 
or different kinds of matter, each particular kind possessing its 
own specific properties; but all of these different kinds of matter 
possess certain properties in common, and the properties which 
are common to all matter are called the general properties of matter. 
Among them are: Divisibility (15), Porosity (25), Impenetra- 
bility (26), Indestructibility (27), Compressibility (29), Expansi- 
bility (29), Elasticity (30), and Inertia (31). 

15. Divisibility. — We know from experience that all larger 
bodies can be divided into smaller bodies. Large pieces of 
stone upon the public road are ground up into fine dust. It is 
impracticable to determine by the aid of our physical senses, 
the extent of this divisibility of bodies, but it is evident from 
the fact that matter occupies space, and is impenetrable, that, 
however small the individual particles may be made, mere 
mechanical division can effect no other change but that of reduc- 
ing the size of each portion. 

In order, however, to account for the changes and conditions 



PHYSICS. 5 

of matter which have been observed, it is assumed that all mat- 
ter consists of particles of definite size called molecules (16). 
The possible physical divisibility of matter, therefore, extends 
to its molecule, but no further. 

16. Molecules, then, are the smallest particles of any given 
kind of matter that can subsist alone, or the smallest particles 
into which any kind of matter can be divided without losing its 
identity or without being changed into some new kind or kinds 
ot matter. 

17. Kinds of Matter. — There are numerous kinds of mat- 
ter. Indeed, the distinct kinds of matter already known are 
countless, and new kinds are daily discovered. It follows from 
what was stated in paragraph 16 that there are as many kinds 
of matter as there are different kinds of molecules, and vice versa. 

18. Substance. — The word substance will be used to desig- 
nate a particular kind of matter. 

10. From what has been said (16) you are to infer that 
molecules are not absolutely indivisible; for, while it is true that 
whenever the molecule of any substance is divided, that sub- 
stance ceases* to exist as to its kind, being converted into some 
other substance or substances, all molecules may be divided into 
still smaller particles called atoms (20), which are, with rare 
exceptions, incapable of subsisting separately or in a free state, 
but which unite with each other to form molecules and are capa- 
ble of being transferred from one molecule to another. 

20. Atoms are the smallest particles of matter that can take 
part in the formation of molecules. They are indivisible, phys- 
ically and chemically (22). 

The reasons for supposing that matter is not divisible without limit, but 
that all matter consists of indivisible particles (called atoms) will be stated 
further on (577580). 

21. Atoms unite with other atoms either of the same kind 
or of different kinds, forming molecules. 

22. When molecules are divided, disrupted or decomposed into their con- 
stituent atoms, these atoms rearrange themselves immediately to form new 
molecules. The division of the molecule is not mere mechanical division, or 
a physical division, but it is chemical decomposition. 



6 PHYSICS. 

23. All changes which take place within the molecule, or which involve 
the division of molecules, belong to the domain of Chemistry. 

24. The subject of the divisibility of matter is so important 
as to justify a recapitulation here. 

With regard to its division, matter may be considered in three 
distinct conditions; namely, its Molar condition, its Molecular 
condition, and its Atomic condition. 

1. Molar matter, or the material bodies (" masses of mat- 
ter") perceptible to our senses. Bodies or masses of matter (1) 
are made up of molecules held together by molecular attraction. 

2. Molecular matter, or molecules (16) composed of atoms 
held together by atomic attraction. The molecule is the small- 
est particle of any kind of matter that can subsist, as it can not 
be divided without being transformed into some other kind or 
kinds of matter. 

j. Atomic matter, or atoms (20) of matter, or particles of 
matter which can not be divided by any means. Atoms unite 
with each other chemically to form molecules, and can pass from 
one molecule to another, but are incapable of separate subsist- 
ence. 

25. Porosity. — Pores are the extremely minute spaces 
between the molecules of bodies. All bodies are pcrous. This 
property is accounted for by the hypothesis that the molecules 
are not in actual contact. 

Distinction should be made between the invisible physical pores, which 
are above referred to, and the sensible pores, which are the actual cavities 
observed in porous substances like pumice stone, filter paper, unglazed earth- 
enware, etc. 

26. We may now refer once more to the impenetrability 
of matter. Since the molecules of a body are not in actual 
contact with each other, tw T o different substances may be inti- 
mately mixed with each other, the molecules of one occupying a 
portion of the space between the molecules of the other, as in 
a solution of sugar in water, but the molecules can not penetrate 
each other (5). 

27. Indestructibility. — Matter can not be annihilated. It 



PHYSICS. 7 

can be changed as to its kind but not as to its amount. The 
amount of matter in the universe can neither be added to nor 
diminished. It is uncreatable as well as indestructible (490). 

28. Contraction and Expansion of Volume.— By reason 
of its porosity (25) matter may be made to occupy more or less 
space without change of mass. Not being in actual contact 
with each other, the molecules may be brought nearer to each 
other by compression of the body or by a reduction of its tem- 
perature ; or they may be separated further from each other by 
the withdrawal of pressure or by the aid of heat. 

20. By the Compressibility of matter we understand that 
masses of matter can be compressed or forced to occupy less 
space without diminution of mass. 

By Expansibility is meant the opposite of compressibility. 
Bodies can be made to occupy more space without any increase 
of their mass. 

30. Elasticity is the property by virtue of which a body 
which has been compressed or expanded by some force exter- 
nal to itself resumes its original volume. 

31. Inertia is a term used to express the recognized ina- 
bility of matter to move without the impulse of some force 
external to itself and its inability to stop of its own accord 
when once put in motion. 

Matter at rest must remain at rest until put in motion by 
some force, and matter in motion must continue in motion until 
its motion is arrested by some force. 

32. Among the specific (or characteristic) properties of mat- 
ter are: Hardness, by which some substances more or less 
strongly resist superficial impression or scratching; Tenacity, 
by which some kinds of matter resist more strongly than others 
an effort to pull their bodies apart; Brittleness, or the property 
of being easily crushed; Malleability, or the property by virtue 
of which some metals may be rolled or hammered into plates 
or sheets, and Ductility, which renders it possible to draw 
certain metals into wire. 

The " specific properties" enumerated and defined in the 



8 FHYSICS. 

preceding lines depend chiefly upon the various states and 
degrees of cohesion and adhesion. 

Other characteristic or specific properties of different kinds of 
matter are such as peculiar form, color, odor, taste, solubilities, 
melting point, boiling point, molecular weight, relative stabil- 
ity of their molecules, etc. 



CHAPTER II. 



FORCES AND PHENOMENA. 



33. Phenomena. — The changes occurring in the form, 
condition, and properties of matter are called phenomena. They 
are caused by forces (34 to 36) operating in accordance with fixed 
laws of nature. 

34. Force is whatever produces, changes, or arrests motion 
(59). It manifests itself under various forms. Like matter it is 
uncreatableand indestructible. It can neither be added to nor 
diminished. 

35. Attraction and Repulsion. — All particles of matter pos- 
sess a tendency to attract and to repel other particles of matter. 
All motion (59) is the result of these pushes or pulls, which are 
caused by the attractive and repellant forces. Attraction and repul- 
sion co-exist, and the resultant motions and conditions of matter 
vary as the one or the other predominates. 

36. All attraction and repulsion between different portions 
of matter are mutual. Thus if the body A attracts the body B 
to itself, A is also attracted by B, and if one particle of matter 
repels another the repulsion is reciprocated. 

37. Attraction is called molar attraction, or "mass attrac- 
tion " when it operates between bodies of matter, or between 
masses of molecules. 

The attraction between molecules is called molecular attraction. 
The attraction between atoms is called atomic attraction, chem- 
ical attraction, or chemical affinity. 



PHYSICS. 9 

GRAVITATION. 

38. Molar attraction affects all bodies at all distances. 
Thus all bodies in the universe are mutually attracted to and 
by each other. The relative measure of this attractive force is 
in direct ratio to the masses of the bodies, and at the same time 
in inverse proportion to the squares of their distances from each 
other. 

The greater the mass of a body, the greater will be the result of its 
attracting force exerted upon other bodies, and the greater also the force with 
which it is itself attracted toward larger bodies. The further apart two bodies 
are from each other, the weaker the attraction between them. 

This universal attraction which operates between all bodies 
is called Gravitation. 

The laws which govern this mass attraction and its relative 
force, direction, and results, are called the laws of gravitation. 

39. The planets and all other bodies in the universe are held 
in their positions by gravitation. 

Gravitation is operative between the earth and any one of the heavenly 
bodies, between the heavenly bodies respectively, between all bodies upon the 
earth's surface, or between any two bodies. 

40. Weight. — The mass of the terrestrial globe being 
greater than that of any other body in its atmosphere we ordi- 
narily take notice only of that attraction which the earth exerts 
upon all bodies upon or near its surface. 

The ruling power by which the earth attracts toward its cen- 
ter other bodies of lesser mass is called weight. 

Thus it is the pressure which a terrestrial body exerts upon a 
horizontal plane which prevents it from falling. 

It may also be said to be the force required to neutralize the 
earth's attraction upon a body on or near its surface. 

41. Gravity. — A body whose gravitation is exactly equal in 
all directions, remains in the same position though it may be sus- 
pended in space. Such a body, in relation to other bodies, has 
gravity but not weight. 

Sometimes " gravity " is defined as "the attraction between the earth 
and bodies, upon or near its surface;" thus, that which we have called 



IO PHYSICS. 

"weight" in par. 40; and when gravity is thus denned, the term weight is 
defined as " the measure of gravity." 

42. Weight is considered in two different ways — 1. As abso- 
lute weight (43), which is weight without reference to volume; 
and 2. Specific weight (47), which is the ratio of weight to volume. 

43. Absolute weight is expressed in units of fixed value 
which are chosen as standards of comparison. The British 
standard of weight is the avoirdupois pound, which is made of plat- 
inum and copies of which are used for weighing things; the 
standard of weight used in science, and in the greater part of 
the civilized world for all other purposes, is the Gram, which rep- 
resents the weight of one Cubic-centimeter of water. 

44. True weight is the weight of a body in a vacuum (9). 

45. Apparent weight is the weight of a body in air or in any 
other fluid (80). 

46. When we say that one piece of iron is heavier than 
another piece of iron, that a pound is lighter than a kilogram, 
or that a cubic inch of water weighs more than a cubic-centi- 
meter of the same liquid, we are comparing their absolute 
weights, and the differences are accounted for by the fact that 
their volumes differ. In other words absolute weight may be 
determined and expressed without reference to volume. 

47. Specific Weight is the relation of the weight of a body 
to its volume. 

It is nearly synonymous with density (10), for the specific 
weight of a body must necessarily be in direct ratio to the mass 
as compared with the volume, and we know that the greater the 
mass of a terrestrial body the greater will be the gravitating 
force by which it is drawn towards the center of the earth (40). 

Specific weight may also be said to be the relative gravitating force o 
one substance as compared with that of a like volume of some other substance. 

48. When we speak of iron as being heavier than chalk, or 
say that ether is lighter than chloroform, it is always under- 
stood that the comparison refers to equal volumes, and the 
weights referred to in this connection are, therefore, the specific 
weights proper to these substances respectively. 



PHYSICS. II 

When equal volumes of any two or more substances are weighed, we gen- 
erally find that their weights differ. That is because their densities differ. And 
the differences in weight caused by differences in density are indicated by the 
specific weights. 

49. In order to express the specific weights of substances 
some one substance must be chosen as the standard of compari- 
son. Thus the standard of comparison adopted for all solids 
and liquids is water, while the standard of comparison now 
used in expressing the specific weight of gases is hydrogen. 

[Formerly the standard unit for gases was the specific weight of air; but, 
for reasons which you will better appreciate as you learn chemistry, it is far 
more convenient as well as scientific to adopt the hydrogen unit.] 

50. Thus the specific weight of water is called 1, and as the 
specific weights of all solids and liquids are expressed in water 
units it follows that any substance which is only half as heavy 
as water has the sp. w. 0.500 and any substance twice as heavy 
as water has the sp. w. 2. As a cubic inch of silver is 10^ 
times as heavy as a cubic inch of water, the sp. w. of silver is 
10.500 (\vater=i); if a cubic foot of glass weighs three times 
as much as a cubic foot of water, the sp. w. of that glass 
is 3.000; since the weight of any given volume of mercury 
is 13.596 times the weight of the same volume of water, the sp. 
w. of mercury is 13.596 (water=i). Ice weighs only 0.930 
times as much as the same volume of water; therefore, the sp. 
w. of ice is 0.930 (water=i.) 

51. In stating the specific weights of gases, we call the sp. 
w. of hydrogen 1, and the specific weights of all other gases are 
expressed in hydrogen units. Thus Oxygen has the sp. w. 16 
(H=i), for a liter of oxygen weighs sixteen times as much as a 
liter of hydrogen; but chlorine is heavier than oxygen, any 
given volume of chlorine being 35.45 times as heavy as an equal 
volume of hydrogen, the sp. w. of chlorine being, therefore, 
35.450 (H=i). 

52. Compared with each other the specific weights of the 
substances used as standards of comparison for other substances 
are aboutas follows at the temperature of 15 C. (59 F.) Water 
1 (water=i), or 11,400 (H.^=i), or 815 (Air=i). Hydrogen 1 



12 PHYSICS. 



(H.= i), or 0.0691 (Air=i), or 0.000085 (water=i). Air i(Air=i), 
or 14.44 (H.=i), or 0.00122 (water— 1). 




Fig. i. Fig. 2. 

Fig. 1 Represents the volume of one grain of air. Fig. 2. the volume of one grain of water. 

Thus water is about 11,400 times as heavy as hydrogen, and 815 times as 
heavy as air (see figures 1 and 2); hydrogen is 0.0691 times as heavy as air, and 
0.000085 times as heavy as water; air is 14.44 times as heavy as hydrogen, 
and o 00122 times as heavy as water. 

53. The expression " specific gravity " is generally used 
instead of the more correct expression specific weight. As com- 
monly employed both expressions mean precisely the same 
thing. 

MOLECULAR ATTRACTION. 

54. Molecular attraction is of two kinds — Cohesion and 
Adhesion. 

55. Cohesion is that molecular attraction which operates 
between the like molecules of a chemically homogeneous body. 

56. Adhesion is the molecular attraction which holds 
together the unlike molecules of mixtures, or which operates 
between the molecules of two or more different substances. 

57. Atomic Attraction governs the relative stability of 
different kinds of matter. It causes the change of particular 
kinds of matter into other kinds when the conditions are favora- 
ble. It renders possible the assimilation of food by plants and 



PHYSICS. 13 

animals. Decay and decomposition, as well as the formation of 
new substances out of the debris, are the results of atomic 
attraction. 

It will be considered further on more fully under the head of 
chemistry. 

58. Energy, which is the power to do work, or to overcome 
resistance, is the product of force (34). A force does work when 
it produces or arrests motion (59). 

59. Motion is a change of place. We are to distinguish 
between molar, molecular and atomic motion. 

60. Molar Motion, or " mass motion," and molar force 
pertain to bodies of matter. 

Dynamics (197) treats of the states and motions of matter in its molar con- 
dition, and of the relations and results of molar attraction and repulsion. 
Dynamics is a more comprehensive term than the expression "mechanical 
science " which treats of the application of dynamics to the accomplishment of 
useful work, the construction of machines to that end, etc. 

61. Molecular Motion, or the molecules within the body 
or " mass," is distinct from both molar and atomic motion. The 
mass may be at rest while its molecules are constantly in motion. 
The motion of the molecule is distinct from the motion cf the 
atoms of which it consists. 

Molecular motion never ceases. 

62. But while the whole body may move independently of 
the motions of its molecules, the several modes of molecular 
motion involve the whole mass, all of its molecules being 
affected. 

Molecular motion is vibratory — not progressive. 

63. Among the modes of molecular motion are Sound, 
Heat (305), Light (412), and Electricity (430). 

64. Atomic Motion, or the motion of the atoms (20), within 
each molecule (16), is doubtless as never-ceasing as molecular 
motion (61), although its existence has not been demonstrated 

In chemical reaction (493), the atoms must be extremely 
active. 

But we must defer the consideration of atomic attraction 



14 PHYSICS. 

and repulsion, and the resultant atomic activity until we reach 
the subject of Chemistry. 

65. Recapitulation. — Having now learned that the various 
modes of molecular motion, or manifestations of energy, are 
what we call sound, heat, light and electricity, we may close this 
chapter by the statement that these several different forms of 
motion are interconvertible. 

66. Correlation of Energy.— Energy of any kind can be 
changed into energy of any other kind.. Thus, the different 
forces are only different forms of one universal Energy and 
mutually interchangeable. 

67. Conservation of Energy. — Whenever any form of 
energy disappears, its exact equivalent in another form takes 
its place, so that the total sum of energy in the Universe 
remains unchanged. 



CHAPTER III. 

PHENOMENA DEPENDENT UPON COHESION. 

68. The three states of aggregation of matter are the 

so/id, the liquid, and the gaseous state. 

69. Solids are bodies in which the molecules are held 
together so firmly by cohesion (55) that they retain their form with- 
out support, under ordinary conditions (of pressure and tem- 
perature), and can be changed as to their form only by external 
violence, or by the influence of heat (375), or by solution (183). 

Ex. — All metals, except mercury, are solids. Rocks, trees, ice, butter, 
paper, cobweb, pieces, panicles of powder, dust — all these are solid bodies. 

70. According to their consistence the solids are hard, soft, tough, brit- 
tle, elastic, rigid, flexible, malleable, ductile, etc. Several of these terms 
will be understood by reference to par. 32, while others explain themselves 
or may be found in any dictionary. 



PHYSICS. 



J 5 



FORMS OF SOLID BODIES. 

71. The greater number of solid bodies do not exhibit any- 
definite or regular form. Yet many organic substances (454), 
formed in plants or animals, show a tendency toward the forma- 
tion of more or less globular masses, and many inorganic sub- 
stances together with a large number of products of the 
chemist's laboratory, have well defined angular geometric 
forms, called cry 'stals (84). 








Figure 3. Figure 4. Figur j 5. 

[See crystalloids and colloids, par. 179.] 

72. Substances occurring in crystals or crystalline masses 
are called crystallic, or crystalline (89) substances; all others are 
said to be amorphous (96), or formless. 

73. Solids which are not altered by exposure are said to be 
permanent in the air. 

Those that absorb moisture from the air are hygroscopic, and 
if they take up so much moisture as to become quite wet, they 
are deliquescent. 

Crystallic and crystalline substances, when they give up 
their water of crystallization (121) on exposure to the air, thereby 
losing their crystalline form, are called efflorescent (123). 

Ex. — Gold, corrosive sublimate, cream of tartar, are " permanent in the 
air." 

Squill and gentian are "hygroscopic." 

Chloride of iron, potassium carbonate and zinc chloride are " deliques- 



Copperas, washing soda and Glauber's salt "effloresce." 



l6 PHYSICS. 

74. Liquids have apparently no form of their own. 

In very small particles of liquids the cohesion overcomes 
gravity (provided adhesion between the liquid and other sub- 
stances do not interfere), so that the molecules, attracted toward 
the center of the mass, form spheres or spheroids, as may be 
seen in drops of dew, globules of mercury or drops of water 
rolling upon a surface dusted with lycopodium. Drops of olive 
oil will float about in a mixture of six cubic centimeters of alco- 
hol and four cubic centimeters of water, the drops of oil exhib- 
iting a perfectly spherical form. 

But when the body of liquid is larger, the force of cohesion 
is overcome by the force of gravity which tends to bring the 
molecules to the same level, and the liquid then assumes the 
shape of the vessel in which it is contained. When the support 
around the body of liquid is taken away, the liquid, impelled 
by gravitation, spreads outward and downward over the solids 
in its way. 

Water is a most familiar and perfect example of liquids. 
Alcohol, ether, chloroform, glycerin, fixed oils, syrups, tinct- 
ures, sulphuric acid and mercury are other examples of liquids. 

75. Liquids are not easily compressed. To compress their 
volume requires very great force; the compression is but slight, 
and on removal of the pressure they immediately resume their 
original volume, being perfectly elastic. 

The enormous pressure necessary to compress water in any 
appreciable degree warrants the conclusion that liquids are prac- 
tically incompressible. 

76. Liquids maybe viscid, like tar, honey, or thick mucilage, 
or they may be mobile, like chloroform; they may be heavy, like 
sulphuric acid, or light, like ether. 

Honey, tolu, storax, oleate of mercury and many other substances are 
frequently in such a condition that it is not easily determined whether they 
ought to be called solids or liquids. 

Very thick, sluggish liquids and solids approaching a liquid 
condition — in other words, substances partaking of the consist- 
ence of both solids and liquids — are called semi-solids, or semi- 
fluids. 



PHYSICS. 17 

They are simply substances whose melting points or con- 
gealing points (376) are the common temperatures of the air 
or of our warehouses, shops and work-rooms. 

77. Gases are aeriform bodies, or bodies like air, which, 
being neither solids nor liquids, do not retain a definite shape, 
or outline of their mass, when put in an open vessel, as the 
cohesion between their molecules is nullified (81). 

Gases, instead of being governed by cohesion (55), resist 
compression (29) of volume by a certain degree of force called 
tension (279). Their molecules, therefore, seem to be governed 
by repulsion instead of by attraction (35). Accordingly, they 
diffuse themselves in every direction through space. 

78. Colorless gases are invisible, and this explains why 
their existence is unknown or unreal to the ignorant. Air, illu- 
minating gas, ''natural gas" (which is mainly marsh gas, or 
methane), gasolin vapor, oxygen, hydrogen, ether vapor, alco- 
hol vapor, are invisible. 

But there are also a few colored gases, as chlorine, which is 
greenish; iodine vapor, which is violet; nitrogen tetroxide, which 
is red, etc. 

79. The term vapor is used to designate gases which exist 
as such only at temperatures above the ordinary, and which, 
under ordinary conditions of temperature and pressure, assume 
the liquid or solid state. 

80. In physics (485) the word fluid is used to designate any 
or all bodies whose molecules easily change their relative posi- 
tions within the mass — in other words, to designate liquids (74), 
gases (77) and vapors (79). 

81. The three different "states of aggregation " depend 
upon the relative force of molecular attraction and repulsion. 
When the attractive force (cohesion) exceeds the repellant force 
the body is solid; when molecular attraction and repulsion are 
equally balanced the body is a liquid; and when the repellant 
force predominates, the gaseous state is the result. 

It is, therefore, said that " cohesion is absent in gases." It 
is, however, not absent, but simply rendered inoperative. 



1 8 PHYSICS. 

82. Many substances are capable of assuming either of the 
three states of aggregation. • Others again only one; and others 
two. 

Carbon is known only in the solid state; lead is known as a solid, and in 
its fused condition as a liquid, but not as a vapor; water is solid, as ice, 
liquid in its ordinary condition, or gaseous as water vapor. 

83. Fixed substances are such substances as can not be 
made to assume the gaseous state. 

Volatile substances are liquids and solids which are very 
easily converted into vapor (79). 



CHAPTER IV. 

CRYSTALLINE BODIES. 

84. Crystals are regular geometric solids with smooth 
faces meeting in straight edges and forming perfect angles or 
corners bounded by three or more of the faces (Fig. 6.) 

Crystals are formed by a definite arrangement of the mole- 
cules of matter in accordance with natural laws. 



Figure 6. 

85. That the crystalline form depends, at least in part, upon 
the attraction called cohesion (55) is self-evident; but it is not 



PHYSICS. 19 

known why or how the molecules of any particular kind of mat- 
ter thus arrange themselves into given forms. 

86. Numerous examples of crystallization are found in the 
mineral kingdom. Mineral crystals formed in the interior of the 
earth were probably produced from matter in a state of fusion 
at extremely high temperatures. 

The remarkably pure calcspar (calcium carbonate) from Iceland, the pure 
silicic acid known as rock crystal, and the highly prized diamond (carbon) are 
beautiful examples of crystals. 

The Iceland spar is a prism, rock crystal is a prism with pyramidal ends, 
and the diamond is a double pyramid (112). 

Galena (lead sulphide) furnishes an example of the cubical form (130). 

But fine specimens of crystals may also be produced in the laboratory, and 
even commercial chemicals frequently exhibit well formed crystals. You 
might find some good crystals of copper sulphate, ferrous sulphate, alum, zinc 
sulphate, lead acetate, quinine sulphate, and many other substances. 

87. There are innumerable forms of crystals, but as a rule 
each particular kind of matter crystallizes in but one form; 
rarely the same substance crystallizes in two or even three 
forms. 

88. As each crystallizable substance generally forms but 
one kind of crystals, the crystalline form is one of the means of 
identification of the respective species of matter. 

Thus, knowing that potassium iodide crystallizes in cubes and in no other 
form, we know also, that any substance exhibiting some other crystalline 
form can not be potassium iodide. 

89. Crystallizable substances are those capable of assuming 
a crystalline form. 

Crystallic substances are those occurring in comparatively well 
defined, free or detached crystals; like copper sulphate, alum, 
potassium bicarbonate, sodium phosphate, lead acetate, quinine 
sulphate, salicin. 

Crystalline substances are those having an evident crystalline 
structure, but not consisting of well developed and detached 
crystals; as ferric chloride, potassium acetate, black antimony 
sulphide, camphor, bismuth subnitrate. 

90. Dimorphism. — Substances capable of crystallizing in 
two different forms are said to be dimorphous . 



20 PHYSICS. 

Calcium carbonate occurs, as calcspar, in rhombohedrons of the hexagonal 
system, and, as arragonite in prisms of the rhombic system. 

91. Polymorphism. — Substances occurring in more than 
one distinct crystalline form are sometimes referred to as poly- 
morphous bodies. 

Trimorphous substances are those occurring in three different 
crystalline forms, of which titanic oxide is an example. 

92. Changes in crystalline form often result from different 
proportions of water of crystallization (121) . 

93. Isomorphous substances are different substances crys- 
tallizing in the same form. 

Entire groups of chemically related compounds may have similar crystal- 
line forms. Bromide and iodide of potassium both crystallize in cubes. 

But the term isomorphism is understood to involve more than similarity or 
sameness of crystalline form (94). 

94. In 1819 Mitscherlich made the important discovery that compounds 
of analogous chemical structure may not only have the same crystalline form, 
but that the corresponding elements in their constitution may be inter- 
changeable in any proportion. The double salts called a/ums are examples of 
perfect isomorphism. They are formed from the sulphates of either potassium, 
sodium or ammonium, with the sulphates of either aluminium, iron or 
chromium, all giving crystals of the same form (Octohedrons), and the 
respective sulphates of potassium, sodium and ammonium are mutually inter- 
changeable, in whole or in part, in these several kinds of alums, as are also 
the aluminic, ferric and chromic sulphates. 

But even bodies not completely analogous as described, may have the 
same crystalline form. 

Mitscherlich concluded that all molecules containing the same number of 
atoms arranged in the same manner have the same crystalline form, without 
regard to the kinds of atoms entering into the molecules. This rule has, how- 
ever, been found to be subject to many exceptions. Kopp regards as iso- 
morphous only compounds the crystals of which can grow in each other's 
solutions. A crystal of common alum will increase in size when placed in a 
solution of iron alum; hence these alums are isomorphous. 

95. Heteromorphous substances are any two or more sub- 
stances which crystallize in different forms. 

96. Amorphous substances. — Literally translated the 
word amorphous means formless. In chemical physics and in the 
description of pharmaceutical chemicals and other substances 



PHYSICS. 21 

the term is used to designate substances without any indications of 
crystalline structure. 

97. It is not to be supposed, however, that the forms assumed by all 
amorphous solids are devoid of regularity when their molecules are permitted 
to range themselves in comparative freedom. On the contrary where the 
straight lines and the perfect angles and faces of the crystal are absent, we may 
expect indications of a tendency to a spherical or bead-like form. 

Substances which take part in the physiological processes of animal or 
vegetable life, belonging to what has been called "organized matter," have 
not the property of forming crystals, although crystallized substances are fre- 
quently found deposited in the tissues of both plants and animals. 

Amorphism is the rule and the crystalline form exceptional among nat- 
ural products derived from the animal and vegetable kingdoms. 

Cellulose, starch, gum, albumen, and many other proximate principles 
contained in plants, are amorphous. 

Examples of inorganic amorphous solids are found in clay, ferrous sul- 
phide, zinc oxide, ferric hydrate, basic ferric sulphate, aluminum hydrate, 
precipitated calcium phosphate, and yellow oxide of mercury, as prepared in 
accordance with the pharmocopceias. 

98. Many substances occurring in amorphous conditions may, however, 
also exist in crystalline forms. Moreover, numerous substances, which to the 
unaided eye appear without the slighest evidence of crystalline form, and 
which occur as impalpable powders, and are, therefore, described as amorph- 
ous, consist in reality of minute crystals plainly visible under the micro- 
scope. The latter may be called micro-crystalline. 

99. When liquids are divided into minute particles, each particle assumes 
a spherical form by virtue of the force of cohesion, and retains that form until 
its cohesion is overcome by some other force, as by adhesion. A drop of oil 
retains its spherical form when floating in a liquid of equal density in which 
the oil is insoluble; but it loses its form when resting upon the surface of 
some solid. 

100. Crystals grow from without by the deposition of 
additional solid matter upon their surfaces. Each larger crys- 
tal is then an aggregation of innumerable smaller crystals of the 
same form. Each smallest crystal in such an aggregation may 
be regarded as an individual. Whether or not the crystalline 
form represents the form of the molecule itself is a secret of 
nature which may perhaps never be discovered. 

101. Being solids, all crystals must of course extend in at 
least three directions. Sometimes their extension is in four 
directions. 



22 PHYSICS. 

CHAPTER V. 

HOW CRYSTALS ARE FORMED. 

102. Axes. — The directions of extension of crystals are 
called their axes. These are imaginary straight lines intersect- 
ing each other at one point in the center of the crystal, and ter- 
minating either in the centers of opposite faces, or in the apices 
of opposite solid angles. 

103. Planes or Faces. — The smooth, plane surfaces of 
crystals are called faces. They are bounded by three or more 
straight sides, each side matching that of the contiguous face. 
The smooth surfaces exposed by cleavage are the faces of crystals. 

According to the number of their faces crystals are called " tetrahedrons " 
when they have four faces, "hexahedrons" when they have six, " octohe- 
drons" when they have eight, "dodekahedrons " when they have twelve faces, 
etc. 

104. Edges are formed by any two contiguous faces. 
These edges, or angles of incidence, or the respective inclination 
of the faces to each other, are characteristic of the primary forms 
of each particular species, and thus furnish the means of deter- 
mining which system crystals belong to, by measuring their 
facial angles. 

This is done with the aid of an instrument called a goniometer. 

105. Angles. — The angles of crystals are the solid angles 
formed by three or more contiguous faces meeting in a point. 

Thus each corner of a cube is a three-faced angle; the apex of a hexag- 
onal pyramid is a six-faced angle; and octohedrons have six four-faced angles 

According to the number of their angles crystals are called tetragons, hex- 
agons, octagons, etc. 

106. Fundamental Forms of crystals are the simple dom- 
inant forms of the several systems (129). 

107. Simple Forms. — Crystals bounded in all directions 
by similar faces are called simple forms, as shown in galena and 
in the diamond (Figs. 7 and 8). 

108. Complex Forms, are those having dissimilar faces, 
as shown in the rock-crystal and the calcspar. Complex forms 
are always combinations of two or more simple forms. 



PHYSICS. 



2 3 



The largest faces in a complex crystal are called the dominant faces 
because they determine the dominant form of the combination. The smaller 
faces are called subordinate ox secondary faces. 





Figure 7. 



Figure 8. 



109. Crystal forms in which all the possible faces are pres- 
ent, making the crystal complete, are called holohedral forms. 

When only one-half of the normal number of faces are pres- 
ent, the crystal being thus only one-half developed, the form is 
called hemihedral. 

Forms with only one-fourth of the normal number of faces developed are 
also known. 

110. Cleavage.— By carefully-directed gentle blows, or 
with the edge or point of a knife, an irregular mass of a crystal- 
line body, or a single crystal, can be split in certain directions 
so that plane, smooth faces are produced. The body can then 
be split into layers parallel with the surfaces thus exposed. 
This is called cleavage. The crystal or mass frequently splits 
more readily in one direction than in others. 

A perfect crystal may thus be obtained by the dissection of an apparently 
shapeless mass in the directions indicated by the cleavage. 

The simple form from which a secondary form is derived, may be discov- 
ered with the aid of cleavage dissection. Thus a hexagonal prism of Iceland 
spar may be reduced by cleavage to an obtuse rhombohedron. 

111. The axis of symmetry is an imaginary straight line 
drawn through the center of the crystal, and around which its 
parts are symmetrically arranged. 



24 PHYSICS. 

112. Three general forms of crystals are to be distinguished: 
the cubical form, the prism or long columnar form, and the pyra- 
mid or pointed form. 

These forms are modified and combined into numerous varieties. Thus 
there are prisms with pyramidal ends, double pyramids, or two pyramids 
placed base to base. etc. 

The cube is seen in potassium iodide; the prism in Rochelle salt; the 
pyramid in potassium sulphate. 

113. Prisms are called open for ms because their lateral faces 
are parallel so that the length of the crystal is indeterminate. 

Pyramids and double pyramids are called closed forms because 
they terminate at the apices. 

1 14. Crystalline structure in soluble bodies when not apparent on the sur- 
face, or when so confused that the form can not be recognized, may often be 
discovered by slow solution of the broken crystals on the exterior. This may 
be affected by means of a nearly saturated solution of the same substance, 
such a weak solvent being sufficient to break down the fragments of already 
broken crystals but not sufficient to overcome the cohesion of whole faces and 
angles. 

115. Crystalline form as an evidence of definite chemi- 
cal composition. — Only bodies having a definite chemical 
structure are capable of assuming the crystalline form. 

A substance known to be crystallizable is less liable to sus- 
picion as to its purity when in crystals than in any other condi- 
tion. But a crystallic form is far from sufficient evidence of 
purity, for not only do isomorphous substances crystallize 
together, but the crystals of one salt, however distinct, may still 
contain small amounts of heteromorphous salts as impurities. 

116. Crystallization is resorted to as a means of separating 
salts from each other, and thus for purposes of purification, 
because substances which do not crystallize in the same form do 
not crystallize together in the same crystals. 

Perfect purification or complete separation by crystallization is, however, 
difficult unless the several substances to be thus separated from each other dif- 
fer in solubility, when the less soluble substance will crystallize before the 
more soluble one. 

117. The presence of one substance in the solution of 
another may have the effect of causing the latter to crystallize 
in the form peculiar to the other. 



PHYSICS. 25 

Thus, if a solution contain the sulphates of copper and iron (ferrous), 
and there is more than one molecule of ferrous sulphate present for every 
eight molecules of the copper sulphate, the copper salt will crystallize in mon- 
oclinic prisms, which is the form of the crystals of ferrous sulphate, instead 
of in the triclinic form, which is the normal form of crystals of copper sul- 
phate (Lecoq de Boisbandran). 

118. Crystallization. — Crystals are most readily and com- 
monly formed when substances pass from a liquid or a gaseous 
condition into the solid state. 

Crystallization may, however, also take place in a solid body without 
previous fusion, solution or vaporization, as for instance in arsenous oxide, 
which slowly changes from the colorless, glassy, transparent amorphous to 
an opaque, white, crystalline condition. A similar change from a glassy 
structure to a more or less distinctly crystalline character is also to be seen in 
so-called barley sugar, or melted candy, as when clear lemon drops change to 
an opaque condition. 

119. How crystallization is effected. — Solution, fusion and 
sublimation are the usual means of inducing crystallization. 
Large, well-defined crystals are frequently obtained when crys- 
tallizable salts slowly deposit from solutions of suitable degree 
of concentration. Highly developed crystalline forms are also 
sometimes obtained by fusion and by sublimation. Minute 
crystals are often formed when new compounds are produced 
by precipitation. 



CHAPTER VI. 

WATER OF CRYSTALLIZATION. 



120. Anhydrous crystals are those which contain no water 
of crystallization (121). 

They may, however, contain small amounts of interstitial water impris- 
oned between the individual crystals. In that case they often burst asunder 
with a slight explosion when heated. This is called decrepitation, and sodium 
chloride affords a familiar illustration of it. 

Heat a crystal of common salt and see how it bursts with a smattering 
noise. 



26 PHYSICS. 

121. Hydrous crystals contain water essential to the crys- 
talline form. 

The water entering into the composition of hydrous crystals 
is called water of crystallization. 

122. Some salts combine with various proportions of water 
of crystallization, according to the temperature at which the 
crystals are formed, assuming different forms according to the 
amount of water they take up. 

Manganous sulphate crystallized at or below 6°. C. (42°.8 F.) contains 
seven molecules of water; crystallized at from j°. to 20°. C. (44°.6 to 68°. F.) it 
contains five molecules, and when crystallized at 20 . to 30 . C. (68°. to 86°. F.) 
it takes up only four molecules of water of crystallization. 

Sodium phosphate when crystallized from a solution saturated at about 
30 . C. (86°. F.) contains twelve molecules of water; but a solution saturated at 
40 . C. (104 . F.), or over, will, on cooling, deposit crystals with only seven 
molecules of water of crystallization. 

Sodium carbonate as found in commerce contains ten molecules of water; 
at 30 . C. (86°. F.) it may be obtained with nine molecules, at 25 . C. (77°. F.) 
with seven, and at 12 . C. (53. °6 F. ) with five molecules of water. 

Copper sulphate ordinarily crystallizes with five molecules of water. If, 
however, an effloresced crystal of nickel sulphate be added to a supersaturated 
solution of copper sulphate, crystals of the latter salt are deposited which con- 
tain six molecules of water; but if a crystal of ferrous sulphate be instead 
added, the crystals obtained contain seven molecules of water. 

Zinc sulphate ordinarily contains seven molecules of water of crystalliza- 
tion; but when crystallized from a warm (over 30 . C.) concentrated solution 
the crystals formed contain only five molecules of water. 

123. Some hydrous salts readily part with their water of 
crystallization even at ordinary temperatures, losing their crys- 
talline form, usually falling into powder, and are then said to 
effloresce (73). 

Others lose their water of crystallization without losing their 
crystalline form and then become opaque, as acetate of copper. 

At temperatures above summer heat many hydrous salts 
effloresce, and when heated up to about ioo° C. (212 F.), most 
of them give up the greater part of their water of crystallization. 
In many cases it requires very high heat to expel all of the crys- 
tal water, as for instance is the case with the sulphates of zinc 
and iron. 



PHYSICS. 27 

124. Not all of the water of crystallization is held by the 
substance with the same force. 

Magnesium sulphate (Epsom salt) gives up one of its seven molecules of 
water at 30 . to 52 . C. (86°. to 126 . F.); four additional molecules of water are 
expelled by water-bath heat; and by stronger heat the salt may be rendered 
anhydrous. 

Potassa-alum contains 45.57 per cent, of water of crystallization. When 
heated to 40°. C. (104 . F.) it loses about 2.7 per cent, of that water; at 47° C. 
(116. °6 F.) it loses 9.6 per cent.,; at 6o°. C. (140 . F.) it loses most of its water, 
but the crystals still retain to a great extent their form, and the product, which 
is not yet porous, yields a clear solution with water; at 8o°. C. (176 . F.) the 
alum effloresces completely, but still holds a considerable amount of water; 
long continued heating at ioo°. C. (212 . F.) expels all of the water and leaves a 
product which is entirely water-soluble; when heated at once at over 92°. C. 
(197 . F.) the alum undergoes aqueous fusion (538), and the liquid does not 
solidify again until after standing a considerable time; when very gradually 
raised from the ordinary temperature up to 200 . — 205 . C, so carefully that all 
Of the water is expelled without aqueous fusion of the salt, the residue, or 
dried alum, is light and porous; should the heat be too low, a glassy mass may 
be obtained which can not afterwards be rendered porous, and in this glassy 
condition the alum is said to retain fourteen of its original twenty-four mole- 
cules of water. 

Crystallized ferrous sulphate contains seven molecules of water; when 
moderately heated it dissolves in this water of crystallization; between 33 . C. 
(91. °4 F.) and 90 . C. (194°. F.) the salt loses nearly six molecules of that 
water, but to quite expel the sixth molecule requires continued heat at about 
120 . to 150 . C. (248 . to 302°. F.), which is liable to partly decompose and dis- 
color the substance; the seventh or last molecule can not be expelled until 
the heat rises to 280 . C. (536°. F. ) which almost certainly destroys a portion 
of the salt itself. 

Sodium phosphate crystallizes with twelve molecules of water; when 
heated to 35°. C. (95 . F.) it begins to dissolve in its water of crystallization, but 
does not liquefy perfectly until the temperature is raised to about 40 . C. 
(104°. F.); if now allowed to cool again it solidifies into a mass of a radiated crys- 
talline appearance; above 40°. C. (104 . F.) it loses five molecules of the water; 
at ioo°. C. (212 . F.) all of the water is expelled and anhydrous sodium phos- 
phate remains; gradual efflorescence of crystallized sodium phosphate in dry 
warm air, on the other hand, leaves a residue containing seven molecules of 
water. 

125. The water contained in crystallized salts often materi- 
ally affects their color. 



28 PHYSICS. 

Thus the sulphate of copper is blue, and ferrous sulphate bluish-green 
when crystallized; but both are white when dried. Hydrous cobalt chloride 
is garnet red, but the anhydrous blue. 

126. Salts which are decomposed when they come in con- 
tact with water may nevertheless contain water of crystalliza- 
tion, as is the case with normal bismuth nitrate. 



CHAPTER VII. 

CLASSIFICATION OF CRYSTALS. 

127- Crystallography is the science of naming, classifying 
and describing crystals, and of determining their forms 

Theoretically it is a branch of mathematics; practically it serves as an 
important means of recognizing minerals, salts, and other substances occur- 
ring in a crystalline form. 

128. The numerous distinct forms which the crystals may 
assume depend mainly upon three governing conditions: 1, the 
number of the axes; 2, the angles at which the axes several 
intersect each other; and 3, the lengths of the axes, respectively. 

129. The Six Systems. — The known crystalline forms are 
classed into six principal groups or systems based upon the 
number, andthe relative inclinations and lengths of their axes. 

Five of these systems have three axes; the hexagonal system 
alone has four axes. 

Those systems in which the axes intersect each other only at 
right angles are called Orthometric systems. They are the Regu- 
lar, Quadratic, Rhombic, and Hexagonal Systems. 

Those systems in which a part or all of the angles formed by 
the intersection of the axes are oblique, are called Clinometric, 
and consist of the Monoclinic and Triclinic Systems. 

The six crystallographic systems are as follows: 



PHYSICS. 



2 9 



130. The Regular System. — (The Monometric, or Tes- 
sular, or Cubic System.) 

Axes three in number. 

All three axes of equal length. 

Axial angles all 90 . 

The fundamental forms of this system are the cube, the regu- 
lar octohedron, and the rhombic dodekahedron. 

All the axial and facial angles of the Cube are right angles, it has twelve 
edges, its six faces are perfect squares, and its eight equal solid angles are 
three-faced. Each of its faces is at right angles to one axis, and parallel with 
the two other axes. A perfect cube may be built upon its axis by simply 
placing a plane at right angles against each end of each axis. 

Gold, silver, platinum, coper, sodium chloride, potassium iodide, and 
many other substances crystallize in cubical forms. 




Fig. 9. 
Regular Octohedron. 



Fig. 11. 
Rhombic Dodekahedron. 



131. The Regular Octohedron is formed by the trunca- 
tion of the solid angles of the cube, or when each end of each 
axis is connected by straight lines (or rather, planes) with each 
end of each of the two other axes. 

The figure thus produced is a double, square-based pyramid bounded by 
eight equal equilateral triangles, has twelve edges, and six four-faced equal 
solid angles. The angles formed by the edges which are in the same planes, 
meeting in the apices of the solid angles, are right angles. 

Diamond, alum, and magnetic iron ore crystallize in regular octohedrons. 

132. By placing a plane in such position that it connects 
two axes but runs parallel with the third, or by replacing each 
of the twelve edges of the octohedron, the Rhombic Dodeka- 
hedron results. 



3° 



PHYSICS. 



This has twelve equal rhombic faces, and fourteen solid four-faced angles. 

Garnet phosphorus and cuprous. oxide crystallize in dodekahedra. 

133. In addition to these forms there are others, less simple. Combina- 
tions of the simple forms can be easily imagined. Thus we may imagine a 
cube and an octohedron with axes coinciding with each other in all respects 
except that the axes of the cube are somewhat shorter than those of the octo- 
hedron; the result would be an octohedron with all its solid angles slightly 
truncated by the faces of the cube. (See Plate B.) 

Galena and lead nitrate show such compound forms. 

For the purposes of this book, these examples of the manner in which the 
simple forms may be modified, are sufficient. Similar modifications occur in 
all the six systems. 




< 



—J- 



>i 



Fig. 12. 
Double Six-sided Pyramid. 



Fig. 13. 
Six-Sided Prism. 




Fig. 14. 
Quartz Crystal. 



134. The Hexagonal System. (The Rhombohedral Sys- 
tem.) 

Axes four in number. 

Three of these axes are of equal length, and they are called 
the secondary axes. 

The fourth axis, which is called the primary axis, is either 
longer or shorter than the other three. 

The secondary axes are all in the same plane, and cut one 
another at angles of 6o° '. 

The primary axis is at right angles to the plane of the other 
three. 

The fundamental form is the double six-sided pyramid, 
bounded by twelve equal isoceles triangles, and having eight 



PHYSICS. 



31 



solid angles, two of which (one at the apex of each pyramid) are 
six-faced, the other six being four-faced. 

Other important forms are the regular six-sided prism and 
the rhombohedron. Rhombohedrons are formed by extending 
alternate faces of the hexagonal pyramid until they cover the 
others. 





Fig. 25. 
Rhombohedron. (Hemihedral.) 



Fig. 26. 
Combination of Rhombohedron 
and Prism. 




Many substances crystallize in hemihedral 
forms of this system. 

Calc spar, rock crystal, ice and sodium nitrate crystal- 
lize in forms belonging to the hexagonal system. 

135. The Quadratic System — (The Di- 
metric, Square, Prismatic, Pyramidal, or Tetra- 
gonal System). 

Axes three in number. 

The two secondary axes are of equal length . 

The third or primary axis, longer or shorter than the other 
two. 

The axial angles all 90 . 

Pyramids of this system have square bases. 



Fig. 27. 
Scalenohedron with 
Inscribed Rhombo- 
hedron. 



32 



PHYSICS. 





Fig. 28. 
Square-based Double Pyramid. 



Fig. 29. Fig. 30. 

Prism of Quadratic System. Form seen in the Sulphates 
of Magnesium and Zinc. 






Fig. 31. 

Crystal of Potassium Ferro- 

cyanide. 



Fig. 32. 

Quadratic Prism with 

Pyramidal Ends. 



F ig- 33- 
Crystal of Stannic Oxide. 



The primary forms are the double four-sided, square-based 
pyramid and the right square prism. 

Potassium ferrocyanide, mercuric cyanide, magnesium sulphate and zinc 
sulphate crystallize in forms of this system. 

136. The Rhombic System. — (The Trimetric, or Right 
Prismatic System.) 

Axes three in number. 

All the axes are of unequal lengths. 

The axial angles all 90 . 



PHYSICS. 



33 





Fig. 34- 
Rhombic Pyramid. 



Fig. 35- 

Rhombic Prism, with Pyramidal 

Ends. (Zinc Sulphate). 




Crystal of Potassium 
Sulphate. 



The fundamental form is the right rhombic double pyramid, 
or rhombic-based octo-hedron. 

Sulphur and potassium sulphate crystallize in forms belonging to this 
system. 






Fig. 37- 
Monoclinic Double 



Fig. 38. 
Crystal of Sodium Acetate. 
(Monoclinic Prism.) 



Fig. 39. 
Crystal of Cane Sugar. 



Pyramid. 

137. The Monoclinic System.— (The Monosymmetric or 
Oblique Prismatic System.) 

Axes three in number. 

All the axes are of unequal lengths. 

The two secondary axes are at right angles to each other. 

The primary axis is at right angles to one of the secondary 
axes, but forms oblique angles with the other. 

The primary form is the monoclinic pyramid. 



34 PHYSICS. 

Ferrous sulphate, borax, potassium chlorate, sodium acetate, sodium 
thisosulphate, sodium sulphate, sodium carbonate and sodium phosphate 
furnish examples of monoclinic crystals. Cane sugar also crystallizes in 
forms of this system. 

138. The Triclinic System. — (The Asymmetric, or 
Doubly Oblique Prismatic System.) 

Axes three in number. 

All the axes are of unequal lengths. 

All the axial angles oblique. 

This is consequently the least regular of all the systems. 



Fig. 40. Fig. 41. Fig. 42. 

Crystal of Gypsum. Triclinic Prism. Calcium Truosulphate. 

The fundamental form is the triclinic pyramid. 
Copper sulphate, potassium bichromate, boric acid, manganous sulphate 
and bismuthous nitrate crystallize in triclinic forms. 

139. Cubes belong to the Regular System. 

Prisms are to be found in all except the Regular System. 

Prisms with rectangular sides belong to the Hexagonal System if six- 
sided; to the Quadratic System if four-sided. Prisms with oblique angles or 
rhomboid sides and bases belong to the Monoclinic System, if any two of their 
axes are at right angles; to the Triclinic System when they have no right 
axial angles. 

Pyramids belong to all of the six systems. 

Those with square bases belong to the Regular System if the three axis 
are of equal length, the faces being then equilateral triangles; to the Quad- 
ratic System when one axis is longer or shorter than the other two, the faces 
being then isoceles triangles. Pyramids with hexagonal bases belong to the 



PHYSICS. 35 

Hexagonal System; their faces are isoceles triangles. Pyramids with rhom- 
bic or rhomboid bases belong to the Rhombic System, when all the axes are 
at right angles; to the Monoclinic System when any two axes are at right 
angles; and to the Triclinic System when there are no right axial angles. 

140. Among the terms used in the pharmacopoeial descriptions of crys- 
tallic substances, the following terms are also found, all of which explain 
themselves, viz.: tabular, laminar, scaly, acicular (needle-shaped), feathery, and 
vuarty crystals, etc. 



CHAPTER VIII. 

ADHESION. 



141. Adhesion is the attraction which operates between 
the unlike molecules of different substances in whatever state of 
aggregation. 

It may operate between solids, solids and liquids, or solids and gases; 
between liquids, or liquids and gases; or between gases. 

Dust, soot and mud adhere to houses, furniture, clothing, and other solid 
bodies; the printer's ink adheres to this page by the same force — adhesion; 
and cements of various kinds are useful on account of their adhesive nature. 

142. Adhesiveness. — Many substances are adhesive or 
sticky; but their stickiness is by no means sufficient evidence of 
their strength or utility for the purpose of holding solid bodies 
together. Nor does anyone adhesive substance show the same 
adhesion for all other substances. 

143. Dry, hard solids are not adhesive in that condition; but may 
become so upon being moistened or dissolved, and then the strength of their 
adhesion is generally greatest upon again drying or hardening in contact with 
the surfaces to which they are applied. 

144. Viscous substances like tar, honey, etc., may be very sticky and 
yet useless as agents for fixing solids firmly together. 

The strong adhesive power of cement, glue, mucilage and varnish, is 
familiar to you. The best grades of glue and of hydraulic cement have an 
adhesive strength equal to about five hundred pounds to the square inch. 



36 PHYSICS. 

145. But different kinds of adhesive substances are used for different 
materials. Cement is used to hold stones together; mortar for stone and 
brick; glue for wood; mucilage for paper; gum-resins for glass, etc. 

Glue adheres to wood but not to metals; pitch sticks to your fingers if 
they are dry but not to wet fingers; mucilage adheres to paper and cloth, but 
not to greased paper or cloth. 

146. Dry gum (acacia) is not sticky, but a strong solution of gum (muci- 
lage) is remarkably adhesive. Dry resin (common "rosin") is not sticky, 
but a solution of it in either alcohol or oil of turpentine exhibits a strong 
adhesion, while a solution of resin in olive oil is sticky but does not consti- 
tute a good or strong cement because it does not dry. 

147. In all the instances described in the preceding, the adhesion, 
although a molecular attraction, seems to operate only between whole bodies 
of molecules and not between the molecules themselves, but the attraction is 
only between the molecules which form the surfaces of respective bodies 
which adhere together. . 

There are, however, very common and important phenomena of adhesion 
extending to each and all of the molecules of the bodies concerned as in solu- 
tion (183). 

148. Heterogeneous bodies, or mechanical mixtures are 

sometimes so coarse that we can readily recognize the several 
ingredients in them and thus see that they are composed of 
unlike masses of molecules, although the ingredients may adhere 
sufficiently to form one mixed body. 

Building mortar made of sand, lime and water, is easily seen to be a 
mixture. 

149. Miscibility. — When dry solids are mixed with each 
other, as in " species " or mixed teas and in compound powders, 
there may be but faint signs of adhesion between the several 
ingredients. 

Liquids between which there is no adhesion are not micible 
without the intervention of other substances; thus water and 
oil, mercury and water, chloroform and water, do not mix (195 
and 196). 

When solids and liquids are brought into contact with each 
other, the solid is wetted by the liquid if there is any adhesion 
between them, but otherwise not. Mercury does not wet the 
bottle containing it, while water does; but water does not wet 
a greased dish. 



PHYSICS. 37 

150. Pharmaceutically homogeneous mixtures are 

mechanical mixtures so well prepared, or in which the ingre- 
dients are so intimately blended, that they appear as if perfectly 
uniform, although they may contain solid masses of molecules 
of different substances. 

A well-made ointment containing an insoluble powder may be made so 
smooth and perfect that the particles of powder can neither be seen nor felt. 

A compound powder may be made so uniform that the different ingre- 
dients can be recognized only by the aid of the microscope. 

In " blue mass " and " blue ointment," if properly made, no globules of 
mercury are visible to the unaided eye. 

An emulsion of a fixed oil can be so thoroughly prepared that no oil 
globules can be detected in it except with the aid of a good microscope. 

Yet, tn all of these mixtures the ingredients consist oi large bodies of 
molecules, each particle of each ingredient containing numerous molecules. 

151. Mere mixtures may, indeed, sometimes be so intimate 
as not to be recognizable as mechanical mixtures, except by 
chemical means. 

The air is a mixture of oxygen and nitrogen so perfect that the compo- 
nent ingredients are not to be detected by physical means; but the air pos- 
sesses the properties of both gases, and is in reality a mere mixture of the 
molecules of oxygen with the molecules of nitrogen, and the completeness of 
the mixture is not affected by the proportions. 

It is to be remembered that gases diffuse between each others molecules 
in this intimate manner because their molecules tend to separate from each 
other (77). 



CHAPTER IX. 



CAPILLARITY AND OSMOSIS. 



152. Capillarity. — If you place a perfectly clean glass plate 
in a vertical position in a vessel of water, the water will ascend 
on each side of the plate to a height of nearly one-sixth inch, 



38 



PHYSICS. 



being drawn up by the adhesion between the glass and the 
water, the force of that adhesion being greater than the cohesion 
between the molecules of water to that extent. 

But the column of water above the surface must in this case be supported 
not alone by adhesion between the glass and the water, but aided by the 
cohesion in the water itself. 

153. If a second plate of glass be placed parallel with 
and close to the first, the water will rise between the two 
plates higher than it did when only one plate was used, and, 
within certain limits, the column of water between the plates 
will be higher, the nearer the plates are brought to each other. 

When the plates are j^ inch apart, the water will rise between them to 
the height of two inches. 



154. If the two plates are so placed as to 
form an acute angle as shown in fig. 43, the 
water rises highest at the point where the plates 
touch each other. 




Fig. 43- 

155. If a number of tubes of different diam- 
eters be placed together in a tumbler half filled 
with water, the water will rise in each tube a 
different height in inverse proportion to the 
diameter of the tube. The smaller the diameter 
of the tube, the higher the column of water in it. 
Fig. 44- 




Fig. 



In a tube of T ^ inch diameter the column of water supported by the 
adhesion between the glass and the water will be four inches high. 

156. All of these phenomena are caused by adhesion, and 
the form of adhesion which causes liquids to rise upon the sur- 
faces of solids is called capillary attraction or capillarity, because it 



PHYSICS. - 39 

is most strikingly evident in tubes of such small diameters as to 

resemble hairs. 

157. Capillary attraction is most familiar 

to us through the action of blotting paper 

and of lamp wicks. The blotting paper 

absorbs ink, water and many other liquids 

by its capillarity. Lamp wicks carry the oil 

from the reservoir or fount of the lamp to 

the burner. 
Fig. 45. 

158. If a lamp wick or a strip of toweling be placed with 
one end in a vessel containing a liquid, the other end hanging 
down into an empty vessel (Fig. 45), it acts as a siphon (297). 

159. The reason why a liquid can not easily be poured out 
of a full tumbler, or other vessel having no lip or flaring rim, 






Fig. 46. Fig. 47- 

Illustration of the Utility of the Guiding Rod. 

without spilling and without running down along the outside 
of the vessel, is that the attraction between the liquid and the 
surface of the vessel draws them together. 

To prevent this we may grease the edge or rim of the vessel, to prevent 
the capillary attraction, or we may use a guiding rod to divert it (Fig. 47). 

Lips are formed on graduated glass measures (" graduates "), pitchers, 



40 PHYSICS. 

pans, dishes, mortars, beakers, and other vessels in order to avoid the incon- 
venient results of capillary attraction — spilling, and the wetting of the outside 
of the vessel. 

Lips and guiding rods give the proper directing to the stream. 
160. But capillary attraction is exhibited only when the 
liquid wets the surface of the vessel or tube (149). 

As water wets glass while mercury does not you will find that water 
poured into a small graduate or tube forms a concave surface being drawn 
upward along the edges, while mercury, on the contrary, forms a convex 
surface. 

161. A dry lamp-wick or dry blotting paper will absorb and convey any 
liquid which wets it; but if the wick or paper be saturated with one liquid it 
will not afterwards convey another liquid immiscible with the first. Thus a 
lamp-wick wet with water will not draw oil, nor will a wick saturated with oil 
take up any water. 

162. In U-shaped tubes such as shown in Figures 48 and 
49, mercury not only forms convex surfaces in both branches, but 
is depressed in the smaller branch, while water forms concave 
surfaces in both branches and ascends higher in the smaller 
branch than in the larger. 
Fig. 48. Fig. 49 . 

163. But not all liquids affected by capillarity rise to the 
same height in tubes made of the same material; nor does any 
one liquid rise to the same height on one solid as on another. 

In a glass tube we find that alcohol does not rise much over one-half as 
high as water, nitric acid three-fourths as high, but a solution of ammonium 
carbonate higher than water does. On the other hand, mercury rises on lead 
and zinc although it does not rise in glass tubes. 

164. It has been shown that liquids do not rise on solids unless the adhe- 
sion between the solid and liquid exceeds one-half of the force of the cohe- 
sion of the liquid. 

165. If you put a strong water solution of ammonium chloride, or of 
lead acetate, in a shallow dish, and allow it to stand sufficiently long, solid 
matter will deposit along the edge of the surface of the solution, portions of 
the solution will rise by capillary action upon the solid particles and above 
them and (by spontaneous evaporation) deposit more solid matter, and this 
may continue until a crust of solid creeps over the edge of the dish and con- 
tinues on the outside. 

166. In the extraction of soluble matters from plant drugs, 
as in making tinctures, fluid and solid extracts, etc., the 




PHYSICS. 41 

menstruum or solvent used is absorbed into the particles of the 
drug by capillarity. By this force the water, or diluted alcohol, 
or even undiluted alcohol to some extent, is made to permeate 
every particle of the powder used. 

167. Capillarity is absolutely necessary to vegetation and animal life. 
In dry seasons water is drawn to the surface of the ground by capillary action; 
the ascent of sap in plants, and the circulation of the fluids in the tissues of 
plants and animals is in great measure caused by the same force. 

168. Diffusion of Liquids. — Miscible liquids (149) have a 
tendency to mix with each other, without any stirring or shak- 
ing, and even in apparent opposition to the law of gravitation. 
This tendency is called diffusion. 

"\ 7" Put some water, colored with red ink or cochineal, into a tall 

V J bottle or in a graduate; make a solution of one ounce of washing 
soda in four ounces of hot water and filter it; then pour the solution 
slowly through a thistle tube (Fig. 50), into the same bottle keeping 
the end of the tube at rest near the bottom of the bottle until all 
of the solution has been added. If you do not have a thistle tube, 
put the soda solution in the bottle first and then add the colored 
water, pouring this cautiously and slowly down along the sides of the 
bottle so that the two liquids will not mix. As the soda solution is 
denser it will temporarily remain at the bottom under the lighter 
water. But the tv/o liquids become gradually mixed with each other 
by diffusion until in the end the mixture is perfectly uniform. 

You may perform the same experiment with other liquids of 
different densities, as alcohol and water, water and glycerin, etc., 
coloring one of the two liquids used so that the result may be readil:/ 
Fig. 50. seen. 

The diffusion is uniform only in dilute solutions. 

169. A bladder has no visible pores, and indeed, if you nearly fill a dry 
bladder with water and let it stand in an open vessel, no water will escape 
through the membrane . Water will be absorbed into the substance of the 
bladder, but no drops of water will appear on the opposite side. If you tie 
the bladder so tightly near its opening that no water can escape at that point, 
and then place the filled bladder in a screw press and apply pressure grad- 
ually, no water passes out of it until it bursts. You would regard it, there- 
fore, as water-tight. 

Parchment paper, also, holds water, although, like a bladder, it is wetted 
by water and absorbs that liquid into its substance; but it has no visible pores. 

170. Yet, when such a membrane is placed between two liquids both 



42 PHYSICS. 

capable of wetting it, currents may pass through the septum in either direc- 
tion, according to their kind and respective densities. 
Cell walls act in the same way. 

171. These membranes or septa must, therefore, be porous diaphragms, 
notwithstanding the fact that no pores can be seen in them even when exam- 
ined with the highest powers of the microscope. 

172. Osmose. — The diffusion of liquids through membranes 
(as described in the preceding paragraphs), is called osmose. 

173. Osmose evidently depends upon capillary action (159 
to 168). 

174. The osmotic currents pass through the membrane in 
both directions, to and fro, until the liquids in both sides have 
the same composition. Should the liquids on both sides of the 
septum be the same from the beginning no currents can be 
detected; but if they are different and at the same time miscible, 
osmose takes place and continues until the diffusion has made 
them perfectly uniform. 

175. But denser liquids move more slowly than lighter 
liquids through the membrane. Hence, the current toward the 
denser liquid is stronger than the current in the opposite direc- 
tion . 

176. If a bladder is filled with a saturated solution (188), of potassium 
carbonate (common " potash "), a piece of broom stick inserted in the open- 
ing, the neck tied tightly to the stick, and the bladder then immersed in a ves- 
sel of water, the current of water passing into the bladder may be so much 
more rapid than the current of the solution of potassium carbonate passing out 
of it that the bladder may burst. 

177- Osmose may be accounted for by the assumption that 
organic membranes consist of a network of solid matter, the 
meshes or pores of which are invisible because filled with water, 
this water being held with such force that it can not be expelled 
without destroying the membrane. Liquids miscible with 
water may thus be passed through the pores by the intersticial 
water. 

178. Substances held in solution in water are capable of 
passing through organic membranes by osmose (172 to 177). 
But all water soluble substances do not act alike in this respect; 



PHYSICS 



43 



some substances pass through the septum comparatively rapidly, 
while others only pass very slowly. It is found that the sub- 
stances whose solutions diffuse through the septum most rapidly 
are either crystallizable or somewhat resemble crystallizable sub- 
stances chemically, while the other water-soluble matters — those 
that pass through the septum with great difficult)'-, or very 
slowly, if at all — include all that solidify in gelatinous masses 
like glue, gelatin, and gum, and other substanes forming vis- 
cous solutions. 

179. For these reasons the term crystalloids is applied to all 
substances, which in a state of solution readily diffuse through 
organic membranes, and the term colloids is applied to all water- 
soluble substances which pass through such membranes with, 
difficulty. It should be remembered, however, that crystalloids 
are not all crystallizable, and that colloids do not all resemble 
glue in their external form. 

180. The separation of crystalloids from colloids 
by means of osmotic currents, or by the diffusion of 
the crystalloids through an organic membrane, is 
called dialysis. 

181. It has been found that water will pass 
through an organic membrane far more rapidly than 
alcohol. 

Fig. 51, represents an apparatus used to demonstrate that 
fact. Insert a long tube by means of a perforated cork or rubber 
stopper into a squatty bottle, the bottom of which has been 
removed. Tie a piece of bladder tightly over the open lower end 
of the bottle. Fill the bottle and part 
of the tube with alcohol. Then place ( 

the bottle in a shallow dish containing water. In 

the course of a few hours the liquid will have risen 

in the tube, and, if sufficient time be allowed, the 

water will at last have passed through the bladder in 

sufficient quantity to cause the liquid in the tube to 

overflow at the top. 

182. Dialysis is employed in chemical 

analysis for the separation of crystalloids 

from colloids, and also in the arts and man- 
ufactures for the purification of products, etc. 




Fig- 5i- 




44 PHYSICS. 

CHAPTER X. 

SOLUTION. 

183. Solution is a complete molecular blending of any sub- 
stance with a liquid, resulting in a clear, homogeneous liquid 

product. 

The product of solution is also called a solution. 

The liquid employed to produce the solution is called a 
solvent. 

From the definition given above it will be seen that solution 

extends to the molecules; thus the molecules of the substance 
dissolved are so far separated from each other that the mole- 
cules of the solvent lie between them. Solution is, therefore, 
the most intimate and perfect union that can be effected of any 
substance with a liquid. It is the result of molecular adhesion. 
A solution contains no visible particles of solid matter. 

184. Solubility. — Not all substances can be brought to a 
sta:e of solution. Thus, no solvents are known for carbon, the 
metals, and for numerous compounds. The capacity of any 
substance for being dissolved in a liquid is called its solubility. 
But any one substance may be soluble in one or more liquids, 
while insoluble in others. Whenever the word " solubility " is 
used without specifying the solvent referred to. it is understood 
that solubility in water is meant. Thus, when we say that alum 
is soluble, we mean that it is soluble in water. 

A soluble substance may be either solid, liquid or gaseous. 

185. Ratio of Solubility. — The extent to which any sub- 
stance may be dissolved in any given solvent is also usually 
expressed by the word "solubility." 

Thus we say that the solubility of potassium chlorate (in water) is about 
6 per cent., or about one ounce to the pint. 

Experience teaches that some substances are insoluble, others very spar- 
ingly soluble, others readily soluble, or freely soluble. 

186. Solution modifies cohesion and density. When a solid is dissolved 
its cohesion is diminished, and it is thus rendered liquid. When, on the 
other hand, a gas is dissolved, the molecules of the gas are brought together, 
and the gas is condensed and liquefied. 



physics. 45 

187. The substance dissolved of course always adds to the 
volume and weight of the solvent. 

88. A saturated solution is one in which the adhesion of the 
solvent for the substance acted upon by it is satisfied, or one in 
which the adhesion between the solvent and the dissolved sub- 
stance is neutralized or balanced by the cohesion or the tension 
which oppose it. Such a solution is not capable of dissolving 
anymore of the substance it contains, but may, nevertheless, act 
as an effective solvent for some other solvent. 

A saturated solution of potassium nitrate is incapable of dissolving more 
potassium nitrate, but it can dissolve many other substances. 

189. Solution affords striking illustrations of the extreme divisibility of 
matter. Thus, one drop of a saturated solution of copper sulphate (" blue 
vitriol ") put into a gallon of water will strike a decided blue color on the 
addition of a little strong ammonia water. 

A drop of tincture of chloride of iron in a gallon of water will assume a 
purple color on the addition of a grain of sodium salicylate. 

A grain of sugar of lead will make a gallon of water cloudy and on addi- 
tion of a few drops of diluted sulphuric acid a decided turbidity results. 

190. There are two kinds of "solution" spoken of. 

True solution, or Simple Solution, is a solution in which the 
molecules of both the solvent and the substance dissolved 
remain unaltered. 

Chemical Solution is a solution in which the molecules of 
both the solvent and the substance dissolved disappear or are 
destroyed, other (new) molecules taking their place. 

When a piece of sugar is dissolved in a quantity of water, simple solution 
takes place, because the solution formed contains the molecules of the sugar 
and the water, and no new kinds of matter are produced. The solution 
exhibits the sweetness and many other properties of the sugar, and the solu- 
tion also partakes of the properties of the solvent: in fact, the sugar can be 
recovered again as solid sugar of the same kind as before by simply evaporat- 
ing (390) the water. 

But when zinc is dissolved in diluted sulphuric acid the solution which 
takes place is not simple solution but chemical solution, because the resulting 
liquid does not contain any molecules of zinc (nor any molecules of sulphuric 
acid, if the acid be saturated with the zinc) but does contain molecules of a 
salt called zinc sulphate formed by chemical action and which has entirely 



46 PHYSICS. 

different properties from those belonging to zinc. Upon evaporation such a 
solution you would not get zinc,. but the white crystalline water soluble zinc 
sulphate. 

191. A solvent producing simple solution is called a simple 
solvent, or a neutral solvent, while solvents producing chemical 
solution are called chemical solvents. 

The most common simple or neutral solvents are water, alcohol, ether, 
chloroform, petroleum spirit, glycerin, volatile oils and fixed oils. 

The most common chemical solvents are acids, alkali solutions, and the 
solutions of acid salts. 

192. Substances in solution may be thrown out of the 
solution or precipitated by adding liquids in which they are 
insoluble. 

Gum (acacia) is soluble in water, but insoluble in alcohol; therefore, if 
alcohol is added to a solution of gum (mucilage) the gum is precipitated or 
thrown out of its solution. 

Any resin, as, for instance, benzoin, is soluble in alcohol but insoluble in 
water; hence the benzoin contained in the tincture of benzoin is thrown out of 
solution on the addition of water. 

193. When a water solution of a salt is exposed to such a 
low temperature that congelation results, the ice formed does 
not contain the salt. 

The water freezes or crystallizes (118), and in doing so must separate from 
the solution. As the ice forms gradually, the solution maybe concentrated by 
the removal of the portions of ice as soon as they are formed. Plant juices, 
alcoholic liquids, etc., can be concentrated in the same manner. 

194. Solution is a phenomenon of all pervading importance in its uses 
and results. In animals and plants nutrition would be impossible were it not 
for the liquefaction by solution of the substances appropriated as food 

The universal application of solution in the arts and manufactures ren- 
ders it necessary that it should be carefully studied. 

195. Miscible liquids may be said to be soluble, each in the 
other. 

Thus it may be said that water dissolves glycerin and that glycerin dis- 
solves water, because the two liquids blend perfectly with each other (149). 

196. If you have two miscible liquids, A and B, and if A is 
miscible also with a third liquid, C, it does not follow that B, 
too, is miscible with C. 



physics. 47 

Thus, alcohol and water are miscible, and alcohol is also miscible with 
castor oil, but water and castor oil do not mix at all. 

Water is miscible with alcohol, alcohol with ether, ether with olive oil, and 
olive oil with oil of turpentine, but water does not mix with either ether, olive 
oil or oil of turpentine; the alcohol does not mix with olive oil or with oil of 
turpentine, nor the ether with oil of turpentine. 

The miscibility of one liquid with another, therefore, affords no indica- 
tion of its miscibility with a third liquid. 



CHAPTER XI. 

MOTION. 



197. We have seen (60) that " dynamics treats of the states and motions of 
matter in its molar condition, and of the relations and results of molar attraction 
and repulsion." 

We have also read that Energy (58) is the power to do work, to overcome 
resistance, to produce or arrest motion; and that motion (59) is a change of 
place. 

Again, attraction and repulsion were described (35 and 36), and gravitation 
and weight were defined (38 to 41 incl.) 

The reader is advised at this point to turn back to the paragraphs referred 
to, and to carefully read them over again. 

Remember also that matter \s anything that occupies space and is affected 
by gravitation (3 to 6 incl.) 

198. All matter is in motion (59), and, therefore, the terms 
motion and rest are merely relative terms. 

The earth itself is in constant motion. It moves around the sun at the 
rate of 19 miles per second, and at the same time whirls around on its axis at 
the rate of 1440 feet per second. But when you look at large buildings, or 
any other objects on the earth's surface it does not occur to you that they are 
traveling nearly a thousand miles per hour in one direction, and 68,400 miles 
per hour in another direction, because you are travelling at the same rate your- 
self, together with all the objects around you. 

If to this motion of the globe you add the molecular motions and atomic 
motion, it will not be difficult to see that no material object in the Universe is 
ever absolutely at rest. 



4S PHYSICS. 

199. The Laws of Motion. — Sir Isaac Newton pro- 
pounded the following "laws of motion.*' which are universally 
accepted and are of the greatest importance: 

1. A body continues in a state of rest or of uniform motion in a 
tra ig -". t . 7 . t u . $c its state by a force external to itself. 

(See Inertia, par. 31.) 

2. The change of [quantity of) motion is proportional to force, 

place in the straight line in which the force acts, 
j. To every action there is always an equal and contrary reaction; 
or, the mutual actions of .: ; two bodies are alwa rqual and oppositely 
ted. 

200. The first law simply declares that matter is entirely 
distinct from all force, and that, therefore, matter itself can do 
nothing. 

201. The second law means that any amount of force, how- 
ever small or great, in whatever direction applied, will have its 
corresponding effect, no matter what other forces may be at 
work simultaneously upon the body. The second law is also 
stated in the following words: A given force has the same effect in 

ring or producing motion^ whether the body upon which it acts is 
in motion or at res:; whether it is acted upon by that force alone or by 
others at the same r 

202. The third law is less easily grasped. In modern phrase- 
ology it is merely this: " Every action between two bodies is a stress." 

I: is literally true that when you strike your fist against a stone, the 
stone reacts with equal force. A coat hanging on a hook retains its position 
because the hook reacts with a force equal to the pull of the coat. When a 
ball is fired from a cannon, the cannon recoils with a momentum (204) equal 
tc that of the ball, but the backward motion is much less because of the 
greater weight 0: the cannon If you hold a brick on your hand, the hand 
must press upward against the brick with precisely the same force as that 
with which the brick presses down against the hand. The brick is attracted 
by the earth, and when you turn your hand over and let the brick fall the 
earth moves to meet the brick for the attraction between the two bodies is 
mutual, but the mass of the earth being immeasurably greater than the mass 
of the brick, the earth moves so slightly that its motion is imperceptible. When 
a flying bird beats the air with its wings, the reacting force of the air, being 
greater than the v.eight of the bird, causes the bird to rise. 



PHYSICS. 



49 



203. The velocity of motion refers to the space traversed in 
a given time. 

204. The Momentum of a body is the quantity of its 
motion. It depends upon the mass (7) of the moving body and 
upon the velocity (203) of its motion. 

205. A body of great weight, moving with great velocity, has a greater 
momentum than a body of less weight moving with the same velocity, or a 
body of the same weight moving with less velocity. 

206. The momentum (204) of a slowly moving freight train is greater 
than that of a bullet shot from a rifle, and both have a great momentum — the 
first because of its great weight, the second because of its great velocity. 

207. We apprehend danger from the approach of large masses, instinct- 
ively associating them with great force, and we move out of their path; but 
we pay no attention to small bodies moving toward us. 

208. A pebble thrown against a heavy plate glass window does not break 
the glass, but a large stone thrown with the same force will shatter it. 

209. A large pestle gently placed upon a piece of alum in. the mortar so 
that the whole weight of the pestle rests on it does not crush the alum, but if 
the pestle be elevated and then allowed to fall upon the alum, the piece is 
broken. 

210. Centrifugal force is the tendency of a body revolving 
around a center to continue its motion in a straight line, and 
thus to move further away from that center. In other words, 
it is simply the result of Newton's first law of motion (199). 

The mud is sent flying from the revolving wheels of a rapidly moving car- 
riage, and when the carriage turns a corner abruptly its tendency to move on 
in the straight line of its original direction may cause it to be overturned. 

211. The Center of Gravity of a body is the point at 
which the whole weight of the body may be supposed to be 
centered, or that point at which the entire mass of the body may 
be balanced. 

To support any body it is only necessary to support its center 
of gravity. 

212. In a compact body the center of gravity is within the mass; but in 
a hollow body, like an empty box, bottle, or hoop, the center of gravity is out- 
side of the space occupied by the matter of which the body consists, which is 
also the case in the arrangement represented in Fig. 54, which you can easily 
construct with a tumbler or goblet, two table forks, and a match. The forks 



50 PHYSICS. 

are locked together at about right angles by inserting their respective prongs 

between each other, one end of the match is also inserted between the prongs, 

/^^^T ==: W^\ ' n tne an gl e » an d tne other end of the match 

¥r~~^^^xCj 1S supported on the edge of the tumbler at 

1 dST^^nT^L t ^ le P°^ nt immediately above the center of 

JBrl .;|i § ^"s;-. gravity. Thus you can support two forks on 

^^r\ |j J n# one end of a match, the other end of which 

0r I J^.ji^m .jm rests on the edge of a tumbler, without any 

A^j— '-^^^ other support whatever, and if the tumbler 

Fig. 54- is filled with water you can raise it to your 

lips and drink a portion of the water with the forks still hanging on the end of 

the match. Fig. 54. 

In a solid sphere the center of gravity is, of course, the center of the 
sphere. 

213. Equilibrium. — When a body is at rest, the forces 
which act upon every part of its mass are said to balance each 
other and are said to be in equilibrium. A body is in equilib- 
rium when its center of gravity is supported. 

214. A body is in stable equilibrium when supported in such 
a manner that, when somewhat displaced from its position, it 
re-assumes the same position as before. 

A cone resting on its base is in stable equilibrium. 

A body is in unstable equilibrium when so supported that a 
slight change in its position of equilibrium causes it tc fall 
further from that position. 

A stick balanced in a vertical position on the end of the finger is in 
unstable equilibrium. 

A cone resting on its apex is in unstable equilibrium. 

A body is in neutral equilibrium when so supported that it 
remains at rest in any adjacent position after it has been dis- 
placed. 

A solid sphere is in neutral equilibrium when resting upon a horizontal 
plane, and a cone lying on its side is in the same state. 

215. The base is the side on which a body rests. 

The base of support of a table is the figure formed by straight lines con- 
necting the points where its legs touch the floor. * 

216. The line of direction is the vertical line connecting 
the center of gravity of a body with the center of the earth. 



PHYSICS. 51 

217. Stability. — The broader the base is, and the lower the 
center of gravity, the greater will be the stability of the position 
of the body. 

Hence, a tall stand must have a broad and heavy foot. 

If the line of direction fall within the base the body is stable, if the centre 
of gravity is above and outside the base, or (which is the same thing), if the 
line of direction be outside the base, the body must change its position. 

A ball rolls about easily, especially one of a hard material, like a billiard 
ball, because when it rests, it rests only upon a point. A cylinder, as a round 
lead pencil, resting upon a line, also requires but a slight impulse to move it. 
No elevation of the center of gravity is necessary to start .spheres and cylin- 
ders moving. 

218. Velocities of falling bodies. — All bodies, without 
regard to mass or kind of matter, fall with equal velocity through 
space in a vacuum. 

A feather will fall as rapidly as a bullet through a vacuum. 

But if two bodies of different densities (10), fall through air, 
the denser body will reach the ground first, because it meets 
with less resistance from the air (199 and 202), than the less dense 
b>ody. 

219. When bodies fall through a vacuum there is no reaction 
(199), or resistance; but reaction and resistance are always met 
when bodies fall through any fluid (80). 

220. If several bodies, all consisting of the same kind of matter, but of 
different weights, as for instance, a number of iron balls of different sizes, be 
dropped at precisely the same time from a great height, they will all reach the 
ground at precisely the same time, the smallest ball as soon as the largest. 

Twenty horses together can not run any faster than one horse alone. 

221. The fact that a dense body, like a small glass bottle, falls to the 
floor more rapidly than a cork of equal bulk, makes it appear as if heavy 
bodies fall faster than light bodies; but a quart bottle will fall no faster than a 
homoeopathic vial, and in a vacuum corks and bottles will fall with equal 
velocity. 

222. The falling of bodies to the earth is the result of grav- 
itation (38), which affects all matter alike. While gravity is 
directly proportional to mass (7), and, therefore, a lead bullet 
must be attracted to the earth with greater force than a feather, 
the greater force of gravity acting upon the bullet has more 
work to pefrorm, or has to move a greater load. 



52 PHYSICS. 

For the greater force to do the greater work requires as 
much time as for the lesser-force to do the lesser work (58). 

223. As gravitation operates continuously upon matter, 
being a constant force, a falling body requires accelerated velocity in 
the act of falling. 

224. A body starting from a condition of rest to fall of its own weight 
travels about4. 9 meters in one second. In the start, of course, it had no velocity, 
but as it began to move or have velocity, that velocity increased uniformly; 
its velocity at the end of the first second is such as would, if uniformly con- 
tinued, carry the body a distance of 9.8 meters during the next second. And 
as gravitation continues its pull without the least change, the velocity of the 
falling body continues to increase, so that instead of traversing only 9.8 meters 
the second second, the body falls through 14.7 meters, or three times the dis- 
tance it traveled in the first second. For the same reason the body travels 
through 24.5 meters during the third second, or 5x4.9; during the fourth 
second it falls 7x4.9 meters, etc. 

3 225. A Pendulum, Fig. 55, is a weight 

suspended from a fixed point so as to swing 
(or "oscillate") freely to and fro, alternately 
by momentum and gravity. 

The most common form of a pendulum is a flexible 
steel rod loaded at the bottom with a heavy piece of 
metal called the bob. 

The bar or rod of the pendulum being in a vertical 
position, the center of gravity is at the lowest possible 
point. The pendulum is then at rest. But when the 
bob is moved upward and to one side, and then 
released, the pendulum is carried back to its vertical 
position by gravity, and inertia (31) carries it beyond 
Fig. 55. A Pendulum. that position, raising the bob again on the opposite side, 
until gravity stops the motion and pulls the bob down again. 

226. Pendulums of the same length perform an equal num- 
ber of oscillations at the same place in the same time. 

227. The times of vibrations of different pendulums at the 
same place are proportional to the square roots of their lengths. 

Thus, if one pendulum is four times as long as another, the time of vibra- 
tion of the longer pendulum will be twice as great as the time of oscillation 
(or of vibration) of the shorter one. 



\d^c 




physics. 53 

228. The times of pendulums of the same length in dif- 
ferent places are inversely proportional to the square root of the 
intensity of gravity. 

229. The Seconds Pendulum. — The length of the Pendu- 
lum performing its oscillations in seconds of time in the latitude 
of London (at the Greenwich Observatory) at the level of the 
sea is 39.13929 inches. At the equator its length is 39 inches, 
and near the poles it is about 39.2 inches. 

230. The pendulum illustrates well the two kinds of energy — 
energy of motion and energy of position. 

When at rest the pendulum exhibits no energy whatever. But in raising 
the bob to one side, or elevating its center of gravity, we impart to it the 
■potential energy (ox energy of position), which remains stored up as potential 
energy as long as we hold up the center of gravity, but becomes changed into 
kinetic energy (or energy of motion) as soon as we let it fall. 

231. Potential Energy, then, is stored up energy, which 
is not doing work, but which has the ability to do work when- 
ever released. 

A body, as a weight, lifted up from the earth, being pulled downward by 
gravity, has the ability to fall as soon as its support is removed, and can then 
do work. The body of water in a dam has the power to move a water-wheel 
whenever allowed to fall upon it. A spring when wound up has power to 
turn machinery and to do other work. A stretched rubber band, a bent bow, 
also possesses potential energy of position. 

232. Kinetic Energy, or energy of motion, or actual energy, 
is energy in the act of doing work. 

Thus it is the energy of the up-lifted weight after its support has been 
removed; of the water falling on the water-wheel; of the spring, of the 
stretched rubber band, and the bended bow, when released. 



54 PHYSICS. 

CHAPTER XII. 

WORK AND MACHINES. 

233. Units of Work. — In measuring work done the unit 
in which the work is expressed is the work done in lifting a 
given weight through a given vertical height. 

The English unit is the foot pound, which means the work necessary to 
raise one pound one foot; the metric unit of work is the kilogram meter, which 
means the work done in raising one kilogram through one meter. 

234. But in order to estimate the power of any man, ani- 
mal or machine to do work, it is not enough to determine the 
weight which can be moved by each, and the distance through 
which that weight can be moved; it is also necessary to deter- 
mine the time required to do that work. 

235. The work of carrying 100 pounds 100 yards is the same as the work of 
carrying 10 pounds i r ooo yards; and that work is the same whether it be done by 
a man, ahorse, or an engine, or whether it bedone by one man or several men; 
it is the same amount of work, too, whether it be done in an hour, a day, a 
week, or a year. But the rate of work can only be estimated by taking into 
account the total amount of work done by any given agent in a given time. 
The rate of doing work is usually expressed in horse-power. 

236. It is assumed that a strong Horse is able to perform 
33,000 foot-pounds of work in one minute; therefore that is the 
meaning of the term horse-power; thus 1 horse-power equals 
33,000 foot-pounds per minute, and an engine of 20 horse-power 
is one capable of doing 660,000 foot-pounds of work per minute. 

237. As the momentum of a body is the product of its mass 
by its velocity (203), and as a body gains accelerated velocity 
when acted upon by a constant force (223), it follows that when 
a body falls from a greater height it has greater momentum at 
the end of the time of motion. 

A weight dropped from a height of nine yards will strike a bed of clay 
with three-fold velocity and penetrate to nine times the depth into the clay as 
compared with the work of the same weight when dropped from a height of 
only one yard. 

The work done by a moving body will vary as the mass and 
as the square of the velocity. 



PHYSICS. 



55 



238. A machine is a contrivance by means of which a given 
power may be advantageously used to perform a given amount 
of work. 

239. A Lever is an inflexible bar capable of being freely 
moved about a fixed point or line called the fulcrum at which 
the lever is supported. The power and the weight act on this bar 
at different points. A lever has two arms — the power-arm, and 
the weight-arm, separated by the fulcrum. 

2 40. There are three kinds of levers, differing from each 




Fig. 56. A Balance. 

other according to the relative positions of fulcrum, power and 
weight. 

A" lever of 'the first kind" (see Fig. 56) has the fulcrum between 
the power and the weight, as in the steel-yard, or in a crow-bar, 
a balance, scissors, etc. 

A lever of the second kind has the weight between the power 
and the fulcrum, as shown in cork-squeezers, nut-crackers, 
tobacco-cutters, an oar, etc. 

A lever of the third kind has the power between the weight 
and the fulcrum, as in fire-tongs, sheep-shears, and in the 
treadle of a lathe. 

241. The statical law of the lever. The product of the power 



56 PHYSICS. 

multiplied by its distance from the fulcrum is equal to the 
product of the load multiplied by its distance from the fulcrum. 




Fig. 57. Cork Presser. A lever of the second kind. 

242. Thus in a lever of the first kind, four feet long, if the load be one 
foot from the fulcrum, a power of one pound will balance a load of four pounds 
since 3x1 equals 1x3. 

243. In a lever of the second kind four feet long with the load one foot 
from the fulcrum, a power of one pound will balance a load of four pounds, 
for in this lever the power will be four feet from the fulcrum. 

244. With a lever of the third kind, of the same length as before, if the 
power be applied one foot from the fulcrum, a power of one pound will bal- 
ance a load of only one-fourth pound, for in this case the load is four feet 
from the fulcrum, and 1 x 1 equals 4 x 3^- 

245. The Balance is a lever of the first kind (240), with 
two equal arms. (Fig. 56). 

The center of gravity of this lever must be a little below the edge of the 
fulcrum. This brings it to such a state of stable equilibrium, that it will 
readily return to a horizontal position. 

246. A load carried on a lever be- 
tween two supports will be equally di- 
vided between the two carriers only if it 
be equidistant from the two points of sup- 
port. If, as shown in fig. 58, the load be 
placed only two feet from the first sup- 
port and four feet from the other, the load 
weighing thirty pounds, the first support 
carries twenty pounds of the load and the 

other only ten. 
Fig. 58. 




PHY5ICS. 



57 



247- A Pulley consists of a wheel turning upon an axis and 
having a cord passing over its grooved circumference. 

A single pulley as shown in 
fig. 5Q does not afford any increase 
of power but only a change of di- 
rection; but when two or more pul- 
leys are used together as shown in 
figs. 6o and 6i a greater load may 
be lifted with less power, but also 
with correspondingly less velocity. 
In the machine represented by fig. 
6o it is evident that the hook 
supports one-half of the load and 
the hand pulls the other half up, 
but to raise the load one foot the 
hand must pull up two feet of the 
cord, for each section of the cord 




Fig. « 



F1ff.6c 



Fisr. or. 



carrying the load must be shortened one foot to raise the load" one foot. If 
the hand, therefore, lifts io pounds two feet, a load of 20 pounds will be 
raised one foot. 

With a combination of several pulleys the load which can be raised will 
be still greater in proportion to the power applied, and the ve. b which 

the load is raised will be proportionately lessened. 

248. The Inclined Plane. — The power required to support 
a load on an inclined plane is to the load as the vertical height 
of the plane is to its length. 

Thus, if the plane is twice as long as it is high, a power of 100 pounds 
will support a weight of 200 pounds. 

249. The Wedge is a movable inclined plane, or two 
inclined planes united at their bases. 

250. The Screw is a cylinder with a spiral groove or ridge 
winding about its circumference. It is, in fact, s'mply a spiral 
inclined plane. 

The spiral ridge is called the thread of the screw, and this works in a nut 
in which there is a corresponding groove in which the thread fits 

One full turn of the screw will lift a weight through the distance which 
separates the threads. 

The weight moved is to the power required to move it, as the circumfer- 
ence described by the power is to the distance between the threads. 



58 PHYSICS. 

Thus, a power of thirty pounds applied at the end of a lever two feet long, 
acting on a screw, the threads of which are ^ inch apart, will lift a weight of 
45,300 pounds. 

Hence the great power of the screw press. 

251. Friction is the resistance which a moving body en- 
counters from the surface against which it moves. 

A perfectly smooth surface can not be made, and despite lubrication and 
other means to diminish the resistance, heat is developed by the friction, and 
the mechanical energy is thus converted into molecular motion. Adhesion is 
doubtless closely related to friction. 

252. Hydrodynamics is the dynamics (197) of liquids. 
Pneumatics is the dynamics of air and other gases. 



CHAPTER XIII. 

HYDRODYNAMICS. 



253. Liquids transmit pressure equally in all direc- 
tions. — If pressure is applied from without upon water con- 
tained in a closed vessel, that pressure is transmitted by the 
water in every direction, upward as well as downward and out- 
ward, with the same force as originally applied. That force is 
proportional to the surface to which it is applied. 

Thus, if a pressure of one pound be applied to the water through a tube, 
the opening of which measures one square inch, then there will be a pressure 
communicated to the sides, top and bottom of the vessel amounting to one 
pound to every square inch of their surface. (See also paragraph 257.) 

254. The Bottom Pressure. — Every molecule at the sur- 
face of a body of liquid presses upon the molecule next below 
it, and this next molecule not only transmits the pressure 
exerted by the upper molecule, but adds to that pressure its 
own weight, and so on downward through the whole depth of 
the liquid. The pressure thus increases with the depth, and if 



PHYSICS. 



59 



the liquid be contained in a cylindrical vessel with perpendicu- 
lar sides and horizontal bottom, the pressure upon that bottom 
is equal to the weight of the whole body of liquid. But in ves- 
sels contracted at the top the bottom pressure is greater, and in 
a vessel with a wider top the bottom pressure is less than the 
weight of the whole body of liquid, because the pressure depends 
upon the area of the bottom and the perpendicular height of the water 
without reference to the shape of the vessel. 

" Pressure percolators " of various kinds are constructed on 
this principle. 

255. The Lateral Pressure. — As the pressure is trans- 
mitted equally in all directions (253) and at the same time 
added to in proportion to the depth of the liquid, the pressure on 
the sides of the vessel is equal to that exerted on the bottom of 
it only at the edge of the bottom. Midway between the bottom 
and the surface of the liquid the average pressure is only one- 
half as great as at the bottom, being always proportional to the 
depth. At the surface there is no lateral pressure because there 
is no depth there. 

256. Liquids seek their own level. — When placed in com- 
municating-vessels, as in a U-shaped tube, liquids rise to the 
same level in the different vessels or in the several branches or 
tubes of the same vessel. 

As popular expression puts it: "water seeks its own level." Artesian 
wells operate on this principle, and " water towers " furnish the pressure by 
which water is supplied through pipes to whole 
cities, to high buildings and fountains in public 
parks. 

257. The "Hydrostatic Para- 
dox." — Since the transmitted pressure 
is proportional to the surface to which 
it is applied (253), it follows that in a 
vessel with two communicating tubes, 
one larger than the other, both tubes 
being provided with tightly-fitting pis- 
tons, as shown in fig. 62, a downward 



-s 1 

t 




Fig. 62. Hydrostatic Paradox. 



6o 



PHYSICS. 



pressure applied upon the piston of the smaller tube will produce 
greater upward pressure upon the piston in the large tube, the 
pressure being proportional to the area. 

If the area of a be i square inch and that of b 16 square inches, then a 
downward pressure of i pound on (7 will produce an upward pressure of i 
pound to each square inch upon b, and I pound placed on the piston at a will 
lift 16 pounds on the piston at b (34). 




Fig-. 63. A Hydraulic Press. 

258. The Hydrostatic or Hydraulic Press is based upon 

the principle explained in paragraph 257. 

The "Hydrostatic Press" (Brahma's Press) consists of two cylinders 
communicating with each other by a tube, as shown in fig. 63. The pump 
piston working in the smaller cylinder produces, by the arrangement of the 
valves below, a downward pressure which raises the large piston in the other 
cylinder. The distance of the upward movement of the larger piston will bear 
the same relation to the distance of the downward movement of the smaller 
piston as the pressure on the smaller bears to the pressure on the larger piston. 
If the area of the water pressing upward on the large piston be one hundred 
times as great as that of the water pressed downward in the smaller cylinder, 
the large piston will be raised only T ^ foot, while the small piston is pressed 
down a distance of 1 foot. Thus, on one side 1 pound is moved 1 foot, and on 
the other side a weight of 100 pounds is moved y^ foot, the work done being, 
therefore, the same on both sides (34.) 



PHYSICS. 




Hydraulic presses are much employed in the arts and manufactures, and 
may be seen in the laboratories of many manufacturing pharmacists and chem- 
ists, where they are used to press out liquids contained in wet masses of solid 
matter, etc. 

259. The Law of Archimedes. — A body immersed in any 
liquid or gas is buoyed up [or pushed in an upward direction) with a 
force equal to the weight of its own volume of the liquid or solid in 
which it is immersed. 

This principle is one of great importance and wide applica- 
tion. The upward pressure produced by liquid and gaseous 
media, upon bodies immersed in them is termed the buoyancy of 
fluids. 

260. In Fig. 64 we represent a cubical solid 
immersed in water. Every portion of the surface of 
the cube is subjected to the pressure which the body 
of water exerts in every direction, and which is pro- 
portional to its depth. The lateral pressure is equal 
on all sides (255), and therefore will have no tendency 
to move the solid in any horizontal direction. The 
pressure downward exerted upon the upper surface of 
the cube is, however, less than the pressure upward 
produced upon its under surface, because the pressure of the liquid increases 
with its depth (254). The exact difference between the downward pressure 
from above, and the upward pressure from below, is, in fact, exactly equal to 
the weight of a column of water having the same base and the same height as 
the solid (254). In other words, the upward pressure is greater than the down- 
ward pressure, by the weight of the liquid displaced by the solid. The solid, 
of course, displaces its volume of liquid. 

261. Hence the principle of Archimedes is also stated as fol- 
lows: A solid immersed in any fluid {liquid or gas) loses in weight an 
amount equal to the weight of the fluid displaced by it. 

If a cubic inch of lead be weighed in a vacuum its true weight will be 
obtained; if it be weighed in air its apparent weight (45) will be less than its 
true weight (44) by the weight of a cubic inch of air; if it be weighed in water, 
its apparent weight will be still less, the difference from the true weight being 
now the weight of a cubic inch of water, which is heavier than a cub'c inch of 
air. 

262. If the cubic inch of lead be weighed first in air, and then success- 
ively suspended and immersed in olive oil, oil of turpentine, glycerin, syrup, 
and sulphuric acid, the weights obtained will all differ from each other, because 



Fig. 64. 



•62 PHYSICS. 

all these substances differ in density (10) and specific weight (47) . The lead will 
accordingly be found to weigh as much less in olive oil than it weighed in 
air, as the weight of a cubic inch of olive oil; in the other liquids, the loss of 
weight of the cubic inch of lead will appear to be equal to the weight of a 
cubic inch of oil of turpentine, glycerin, syrup, or sulphuric acid, respectively. 

263. There is, of course, no actual loss of weight of the solid 
in the examples given in the preceding paragraph, for matter can 
not lose weight. The so-called "loss of weight" is simply 
apparent, and instead of representing a loss of weight it repre- 
sents the effect produced by the buoyancy in the liquid or gas in 
which the solid is placed. 

264. The Hydrostatic Balance. — A balance so con- 
structed as to facilitate the weighing of solids suspended in 
liquids is called a hydrostatic balance. 

One form of it is seen in fig. 55. At least one of the stirrups is short, 
and to the support for the pan is attached a little hook from which the solid 
is suspended by means of a thread or wire. 

265. As all our ordinary weighing operations are performed 
in the air, and not in a vacuum, it follows that the results are 
not true, che weight found by weighing in the air being less than 
the true weight by the weight of the air displaced by the body 
weighed. 

266. Our weights are constructed so as to show the " weight in air" 
and not " true weight," and it accordingly follows that a pound-weight made 
of brass is necessarily in reality heavier than a pound-weight made of plati- 
num, for the metal called platinum is about three times as heavy as an equal 
volume of brass, and, therefore, one pound of the alloy we call brass is about 
three times as bulky as platinum. Hence, when used in air, the brass pound 
and the platinum pound balance each other perfectly, or have the same 
weight (apparently), but if weighed in a vacuum the brass weight would be 
found to be heavier than the other. Had the brass weight been so made as 
to represent a pound of brass weighed in a vacuum, and the platinum weight 
to represent a pound of platinum weighed in a vacuum, then, when placed on 
the opposite pans of the balance (or " pair of scales") the platinum weight 
would go down and the brass weight up, and it would be necessary to increase 
the size of the brass weight or diminish the platinum weight to restore the 
balance to equilibrium. 

The saying that " a pound of feathers is heavier than a pound of lead," is, 
therefore, in one sense correct. 



PHYSICS. OJ 

267. Heavy bodies sink in lighter fluids (whether liquids 
or gases), and light bodies float in heavier fluids. 

This will be readily understood upon a little reflection, for the upward 
pressure upon the immersed body caused by the buoyancy of the fluid is 
exactly measured by the weight the fluid displaced (259 and 260), and if that 
weight is less than the weight of the solid itself the solid will sink by virtue of 
its greater weight following the law of gravitation (38), but if the solid weigh 
less than its own volume of the fluid it must of necessity rise, or be pushed 
upward, or float on the surface of the fluid in which it is placed. 

268. If the solid and the fluid in which it is immersed are 
of equal density, equal volumes having equal weights, then the 
solid will neither sink nor float but will remain at rest in any 
position in which t may be put in the body of the fluid. 

269. Camphor floats on water, but sinks in alcohol. Wax floats on 
water, but if alcohol be gradually added to the water, the wax will sink as 
soon as enough alcohol has been added to render the density of the liquid less 
than that of the wax. 

270. A floating body displaces its own weight of the 
fluid. — A piece of wood floating on water is depressed into the 
water just far enough to occupy a space below the surface which 
would be filled by its own weight of water. 

If the wood weighs one pound it sinks down far enough to push away, or 
displace, or occupy the space of one pound of water, below the surface. 
Boats displace their own weight of water; when empty the boat displaces but 
little water and rides lightly, but when loaded it sinks deeper as its load 
increases, and may be loaded so heavily that the weight of the boat with its 
load is greater than a body of water of the same bulk, and then the boat 
founders. 

271. An "empty" bottle floats on water because the bottle and the air 
it contains weigh less than the same volume of water; but the same bottle, 
filled with water, sinks. 

272. Since a floating solid sinks down just far enough to 
displace its own weight of liquid (270), it follows that the solid 
must descend to a greater depth in light liquids than in heavy 
liquids. 

273. Hydrometers. — Hydrometers are instruments con- 
structed on the principle of Archimedes (259) and operates in 
accordance with the results of that principle as described in 
the preceding (270, 271, 272). 



64 



PHYSICS. 



274. Fig. 65 represents Nicholson's hydrometer, consisting of a hollow 
metallic cylinder with a lead basket attached below and a pan supported on an 
upright wire at the top. The weight of the lead basket brings the center of 
gravity to that end of the instrument, causing it to descend some distance 
below the surface when placed in water, the hollow 
cylinder above being also a necessary feature of the 
apparatus, as it is lighter than water, and when 
pulled down by the lead therefore assumes a verti- 
cal position, the whole instrument thus remaining 
in a stable condition of equilibrium. 

The wire which supports the pan has a mark, A, 
upon it. As the hydrometer displaces its own 
weight of whatever liquid it is placed in, and its 
own weight is known, it is used in the following 
manner: The sum of the weight of the instrument, 
and the additional weights necessary to bring the 
instrument down to the point A, represents the 
weight of the liquid displaced. 

275. Assuming that the hydrometer itself 
weighs 100 Grams and that it requires 55 Grams 
more to bring it down in distilled water until the 
surface of the water coincides with the mark A; 
also that it requires 20 Grams (instead of 55) to 
push the instrument down to A in alcohol. Then the displaced alcohol must 
weigh 120 Grams, and the same volume of water 155 Grams, and a comparison 
of the relative weights of equal volumes of these liquids has thus been 
effected. See " specific weight " (47). 

276. Nicholson's hydrometer can also be used to find the specific weight 
(47) of solids insoluble in the liquid in which the instrument may be immersed. 
A piece of the solid substance (not heavier than the difference in weight 
between the instrument itself and the weight of the water it displaces to the 
mark A) is put on the pan at the top, and then enough additional weights 
added to push the hydrometer down to A in water; the solid is then removed 
and weights substituted for it to bring the instrument down to A again; the 
sum of the weights used in addition to the solid in the first case, deducted 
from the total of the weights used in the second case, must give the weight of 
the solid itself, or the sum of the weights which were necessary to take the 
place of the solid in the second experiment. Now the solid is put into the 
lead basket, and the hydrometer replaced in the water and again weighed 
down to A. As the volume of the instrument below the surface of the water 
is now increased by the bulk of the solid, the result will be that the instru- 
ment is buoyed up by an additional force equal to the weight of a volume of 




Fig. 65. Nicholson's 
Hydrometer. 



PHYSICS. 



6S 



water equal to the bulk of the solid, and the instrument is at the same time 
pulled down by the whole weight of the solid. Suppose the solid weighs 7 
Grams; then it will require 148 Grams additional weights to sink the hydro- 
meter to A (assuming, as above, that 155 Grams will be necessary to sink it to 
A in water); when the solid is placed in the lead basket, the instrument will 
not sink down to A without additional weights on the pan unless the solid is 
of the same density as water, it will sink 
deeper if the solid is heavier than water, and 
not as deep if the solid is lighter. Suppose 
it is heavier than water, and that it will, 
therefore, be necessary to take off some of the 
weights on the pan in order to bring the 
hydrometer to the fixed depth. If the sum 
of the weights on the pan be now 147 Grams, 
or one Gram less than was necessary when 
the solid was on the pan above the surface 
instead of in the basket immersed in the 
water, then the solid weighed 7 Grams in the 
air, but only 6 Grams under water, and, con- 
sequently, its own volume of water weighed I 
Gram. 

If the solid be lighter than water it must 
be tied to the lead basket before submerging 
it, and we should then find that 155 Grams 
would be insufficient to send the hydrometer 
down to the mark. Suppose, in such a case, 
it requires 156 Grams on the pan; then, the 
solid weighing 7 Grams, its own volume of 
water must weigh 8 Grams. 

277. The common form of hydro- 
meter is shown in figs. 66 and 67. It 
is made of glass, the small bulb at one 
end is loaded with mercury or shot, 
and the expanded part of the tube 
above is to keep the instrument in an 
upright position. The hydrometer 
sinks to different depths according to 
the density of the liquid in which it is 

placed (270), and the point tO Which it Figs. 66, 67. Hydrometers. 

sinks in distilled water at the standard temperature is marked 1; 




66 PHYSICS. 

specific weights above and below the unit are indicated on the 
scale. If the instrument is constructed to show the specific weight 
of any liquid, whether heavier or lighter than water, the unit (or 
the specific weight i) would be situated at about the middle of 
the stem, but a hydrometer for heavy liquids only has the unit 
at the top, and one for light liquids at the bottom of the scale. 

278. There are several kinds of hydrometers (or areometers), some show- 
ing the specific weight, others with scales of arbitrary "degrees" of density, 
some for heavy and others for light liquids, and several kinds for other special 
uses, or for particular liquids, as alcohol, milk, syrup, urine, etc. 



CHAPTER XIV. 

PNEUMATICS. 



279. The tension of gases. — We have already seen that 
molecules of gases repel each other (77). 

They, therefore, expand indefinitely if they find space to enter. Hence a 
small amount of the gas formed by the burning of a sulphur match soon 
spreads its peculiar penetrating odor through a whole room. 

The force with which gases tend to expand is called their 

tension (77). 

A liquid boils whenever the tension of its vapor is sufficient to overcome 
the atmospheric pressure, which always happens at the same temperature if 
the pressure is the same. 

280. Gases are easily compressed. The resistance offered 
by the gas against compression is its tension. 

281. Mariotte's Law. — The volume of a gas is inversely a s 
the pressure it sustains, at any given temperature. 

Thus if the pressure to which the gas is subjected be doubled, its volume 
of the gas is reduced one half; if the pressure be trebled the volume will be 
reduced to one-third; if the pressure be reduced one-half the volume of the gas 
will be doubled, etc. 



PHYSICS. 67 

Gases under equal pressure expand equally for equal incre- 
ments of temperature (Charles). 

A given mass of gas, measuring one liter under the ordinary barometric 
pressure (287), will measure but one-half liter under the pressure of two atmos- 
pheres (287). 

282. The densities of gases are in direct proportion to the 
pressure to which they are subjected (281.) 

283. Atmospheric air is a mixture of about 79 volumes of nitrogen and 
21 volumes of oxygen. It also contains small amounts of water vapor and 
carbon dioxide. Among the chemical changes which substances are liable to 
undergo when in contact with the air are, therefore: oxidation, the absorption of 
moisture when the air is humid; the loss of moisture when the air is dry, and 
the absorption of carbon dioxide. 

284. Atmospheric Pressure. — The air, obeying the law 
of gravitation, exerts a pressure in every direction upon all 
bodies in contact with the terrestrial atmosphere. This pres- 
sure is equal to the weight of a column of liquid which it will 
sustain, and is very nearly equivalent to 15 pounds to each 
square inch of surface, or 1033 Gm. to each square centimeter. 
At the level of the sea the height of the column of mercury sus- 
tained by the atmosphere averages 29.922 inches or 760 milli- 
meters. 

As the atmospheric pressure is measured by the height of the column of 
mercury in the instrument called a barometer, we find the ordinary pressure 
generally referred to in terms such as "760 millimeters pressure," or 
"barometer at 760 m. m.," or " barometer at 30 inches." 

285. When it is stated that the atmospheric pressure is equal to 30 inches 
by the barometer, the statement means that the weight of a column of air 
reaching from the earth's surface, at the level of mid-tide, to the upper limit 
of the atmosphere, equals the weight of a column of mercury 30 inches in 
height, the columns of air and of mercury being of the same area at the base. 
Hence it will be easily understood that the atmospheric pressure on high 
mountains, where the column of air is of less height, must be less, or must be 
balanced by a shorter column of mercury. It is further to be considered that 
the air is of greater density nearer the surface of the earth than higher up. 
At a height of 4.355 meters above the level of the sea, the barometric pressure 
is only 380 millimeters, or one-half the average pressure at the level, or the 
pressure of one-half atmosphere. 



68 



PHYSICS. 



286. The amount of moisture contained in the air also effects its density 
and pressure. The barometer .rises with the humidity of the air, and falls 
when the moisture condenses and descends as rain or snow. As the humidity 
depends upon the temperature and movements of the atmospheric strata, the 
barometer indirectly indicates changes in the weather. 

287. Atmospheric pressure is also called barometric pres- 
sure. 

The ordinary atmospheric pressure, balanced by a column of mercury 760 
millimeters (30 inches) in height, is " the pressure of one atmosphere;" the 
pressure of twice as high a column of mercury represents "the pressure of 
two atmospheres," etc. 

288. Weight of the Atmosphere. The atmosphere must 
weigh about six quadrillion tons, for it equals a layer of mercury 
covering the entire surface of the globe to the depth of 30 inches, 
and the specific weight (47) of mercury is 13.6. The air in a 
room 12^ feet long, 10 feet wide and 10 feet high weighs 
nearly 100 pounds. 

289. But the pressure of the air, which amounts to about 
15 pounds to the square inch, is not a dow?iward pressure. As 

in the case of liquids it is a pressure distributed in every 
direction. (253 to 255.) 

All bodies on the earth's surface sustain this pressure. The 
human body, which has a surface of about 2,000 square inches, 
must, therefore, sustain a pressure equal to about 15 tons, but we do 
not feel it because it is precisely what is required for our well-being. 
Were this pressure to be removed the result would be destructive to us. 

290. The weight of a body is in no degree added to 
by the pressure of the atmosphere. 

In fact, we have already learned that all bodies are pushed 
upward when surrounded by, or immersed in, the air. 

291. The Barometer. — Figure 68 represents an 
instrument called a barometer. It is designed to indi- 
cate the atmospheric pressure. 

The tube, closed at one end, is filled with mercury 

and then inverted in a vessel also containing mercury. 

In the ordinary barometer the lower end of the inverted 

tube is expanded and bent upward, which renders a 

Fig. 68. separate vessel for the mercury superfluous. The mer- 



'HYSICS. 



69 



cury runs out until the column remaining in the tube measures 
29.922 inches, or 760 milimeters. This proves that a column 
of mercury of that height balances a column of air of the same 
diameter reaching through the whole atmosphere from the level 
of the sea as far up as the atmosphere reaches. 

292. Height of the Atmosphere. — It was formerly sup- 
posed that the atmosphere was about 45 miles high ; but it is 
now considered probable that it is at least 100 miles. 

But, as the height of the mercury of the barometer is only 
15 inches when the instrument is taken upon a mountain 3^ 
miles above the level of the sea, it follows that one-half of the 
whole ocean of air contained in the atmosphere must lie within 
a distance of 3^ miles from the earth's surface. 

293. A column of water equal to the atmospheric pressure 
would measure 34 feet, the mercury being 13.6 times as heavy 
as water. 

294. The pneumatic inkstand, represented by fig. 69, 
operates upon the principle that the atmospheric pressure 
sustains the ink in the inkstand. Whenever the ink in the 
tube of the bottle comes below the level of the curve a bubble 
of air enters and forces a portion of ink out into the tube. 




Fig. 69. 




2 95- Fig. 7° a ^ so illustrates the pressure of the 



atmosphere. If you 

place a thick sheet 

of paper over the 

top, pressing 

down the paper 

tightly, and then 

cautiously invert 

the tumbler, the 

water will not run 

out because the 

atmospheric pressure upward keeps the 

paper in its place and prevents the entrance 

of air into the tumbler. 

296. In a Pipette, which is the name 
of the instrument shown in figs. 71 to 75, 
the atmospheric upward pressure prevents 
the liquid in the tube from running out. 



fill a tumbler with water and 




7 o 



PHYSICS. 



Plunge the instrument into a vessel of water, holding the long tube vertically; 
when the bulb is filled, close the upper end with the finger, and then withdraw 
the pipette out of the vessel. The water remains in the pipette. Now take 
the finger off the upper end of the tube so that air can enter; there will then be 
atmospheric pressure from above as well as from below, and, consequently, 
the water will run down by its own weight. 

297. The Siphon. — Another very useful instrument, operat- 
ing by atmospheric pressure, is the familiar siphon. It consists 
of a bent tube, open at both ends, with one limb longer than 

£ * 




Fig. 76. 



Fig. 77. 



the other. The tube may be rigid, as when made of glass or 
of wood or metal ; or it may be elastic, as when consisting of 
rubber hose. If the short limb be immersed in a vessel of liquid 
and the whole tube filled with liquid by suction at the end of the 
longer limb, the weight of the liquid in both limbs would tend 
to cause a downward flow; the atmospheric upward pressure 
would prevent the liquid from running out if both limbs of the 
syphon were of the same length; but as one limb is longer the 
weight of the liquid in that limb is greater than that of the liquid 



PHYSICS. 



71 



in the other limb, and hence the liquid in the longer limb 
descends while the atmospheric pressure upon the liquid in the 
vessel forces the liquid up into the shorter limb, since otherwise 
there would be a vacuum in the siphon, which can not be. 

298. To start the syphon it may be filled with the liquid, both ends 
being closed with the finger ends before placing it in its position, with the 
short limb in the vessel containing the liquid and the longer limb in the 
vessel into which the liquid or a portion of it is to be transferred. 

299. The syphon will continue to run until the level of the liquid in the 
vessel in which the shorter limb is placed descends below the end of the tube, 
or until the level of the liquid in both vessels coincide should they be so placed 
as to lead to that result. The end of the limb from which the liquid flows 
must always be below the surface of the liquid in the vessel from which the 
current comes. 

300. Wash bottles are 
made as represented by figs. 78 
and 79. Air is blown into the 
bottle through the tube A and 
the pressure thus brought to bear 
on the surface of the water causes 
a stream to flow through B. 

Any ordinary wide-mouthed 
bottle, with a well-fitting stopper 
twice perforated for the glass 
tubes, may be used. The end of 
the glass tube B should be drawn 
to a point so as to contract its 
orifice enough to produce a small 
stream. Figs. 7 8 and 79. 

301. Atomizers consist of two tubes placed in such a position relative 
to each other that a jet of air blown through one of them passes over and near 
the mouth of the other. One is the blast tube, the other the suction tube dip- 
ping into a bottle of liquid. A strong current of air blown through the blast 
tube carries the air along its path with it so as to cause a rarefaction in the 
other tube, diminishing the atmospheric pressure in it so that the atmospheric 
pressure in the bottle will raise the liquid to the mouth of the tube where the 
current of air from the other tube will blow it into fine spray. 

302. Vacuum. — Space void of water is called vacuum. The 
space above the mercury in the barometer tube is the most per- 




PHYSICS. 



feet vacuum that can be produced- it is called the Torricellian 
vacuum . 

But a closed vessel may be deprived of nearly all the air it contains by 
means of an air pump, and in certain pharmaceutical processes a vacuum appa- 
ratus, vacuum pans, etc., are employed with the view to remove atmospheric 
pressure and to avoid the chemical charges liable to result from contact with 
the constituents of air. 

303. The Air Pump. — Fig. 80 represents an apparatus 
for removing the air from a closed vessel,, the sections of its 
principal parts being shown in fig. 81. . 

"The receiver, R, is connected with the cylinder, C, by a long bent tube, 
terminating in a horizontal brass plate. The mouth of the receiver and the 

surface of the brass plate 
are carefully ground so as 
to bring them in contact 
at every point. The edge 
of the receiver is greased, 
so as to make the joint as 
tight as possible." 

"When the piston Pis 
raised from the bottom of 
the cylinder, the external 
air closes the upper valve; 
the air in the receiver ex- 
pands, opens the lower 
valve and fills the cylin- 
der. When the piston is 
depressed, the lower valve 
closes, and the air in the 
cylinder is forced through 
the upper valve out into 
the atmosphere. As the 
Fig. 80. Air Pump. piston again rises, the up- 

per valve is closed, the lower valve opens and the confined air expands into 
the cylinder. At every ascent and descent of the piston, a portion of air is 
removed from the receiver, and this process may be repeated until the ten- 
sion (279) of the air remaining is not sufficient to lift the lower valve. The 
receiver is then said to be exhausted." 




PHYSICS. 



73 




SO 



Ht^L^- 



Fig. 81. 



"The tension of the air in the receiver is 
measured by a gauge which consists of a bent 
tube leading from the receiver to a vessel of 
mercury, H. The external air forces the mercury 
up the gauge in proportion as the tension of the 
air in the tube is diminished. If the exhaustion 
were perfect, the mercury would rise to about 30 
inches. The height of the gauge indicates the 
difference between the pressure of the atmosphere 
and the tension of the air in the receiver." 
"The air pump is also provided with a stop cock, S, fig. 81, to close the 

communication between the cylinder, and receiver when 

required. The stopper, A, is used to admit the external 

air to the receiver. A third valve, T, is usually placed in 

the top of the cylinder to prevent the external air from 

pressing on the piston." 

304. The Magdeburg Hemispheres are two hollow 

brass hemispheres fitting together by an air tight joint, as 

shown in fig. 82. When joined together, the air can be 

exhausted from the globe by means of an air pump. The 

hemispheres will now be pressed together by atmospheric 

pressure, or with a force of 15 pounds to the square inch. 

With a diameter of three inches, the area of the section 

would be seven inches, and hence it would require a force 



of over 100 pounds to pull the hemispheres apart. 




Fig. 8s 



CHAPTER XV. 



THEORIES AND SOURCES OF HEAT. 

305. Heat is that mode of molecular motion which may be 
measured by the expansion of bodies, or which manifests itself, 
under certain conditions, by the sensations of " warmth" and 
"cold." 

306. "Heat" and "cold" are only relative terms. A room, the atmos- 
phere of which seems " hot" to one person, may seem chilly to another. If 
you hold one hand in cold water and the other in hot water, and then sud- 
denly transfer both hands to water which is neither hot nor cold, you will 
find the sensations in your hands reversed. Therefore, cold is not the oppo- 
site of heat, but only a lower degree of heat. 

307. That heat is a mode of motion is now the universally accepted 



74 PHYSICS. 

theory. Nevertheless, a definition or description of what heat really is, or 
what distinguishes it from other modes of molecular motion, is far more diffi- 
cult than to describe what heat does. 

308. Heat expands bodies, or increases their volume, or 
reduces their density, or overcomes their cohesion, or increases 
the distances between their molecules— all of which statements 
mean the same thing. 

This effect of heat is resisted by cohesion (55), and may also 
be opposed by pressure. 

309. When heat is applied to any substance a portion of that 
heat increases the temperature (313) of the suostance, while 
another portion increases its volume, and may, if a sufficient 
quantity of heat is adduced, turn solids into liquids and liquids 
into gases. 

310. Active heat, or sensible heat is that heat which 
increases the temperature of bodies and has the power to cause 
their expansion. It produces upon men and animals the impres- 
sion of " heat " if the heat motion is rapid, or of " cold " if the 
motion be less rapid. Having the power to expand bodies it 
causes the mercury in the thermometer (321) to rise. It is 
energy in ihe kinetie form (232). 

311. Latent Heat is that heat which has performed the 
work of expanding the volume of matter and which keeps up 
this expansion. It performs " interior work " in separating the 
molecules of the body from each other, and while performing 
that work can not at the same time do other work, and it, 
therefore, can not cause the mercury in the thermometer to rise- 
Latent heat is a form of potential energy (231). 

Heat rendered latent is, of course, not lost or destroyed (34 and 67). It 
can be released again, or recovered, in precisely the same amount of energy, 
or as active heat, by the compression of the body it expanded. 

312. If a quantity of broken ice be placed in a dish and the dish placed 
ever the fire, the ice will melt, but a thermometer placed in the mixture of 
water and ice will not vary its indication of temperature; the mercury will 
remain at zero C. (32° F.) until all the ice has been melted. If the heat be contin- 
ued the temperature of the water will now, since the ice has all been melted, rise 
until it reaches ioo c C. (2I2 C F.), and there it will stop again: the water will now 
boil and the temperature will remain stationary until the water is vaporized. 



PHYSICS. 75 

and the vapor formed will be found to have the same temperature as the boil- 
ing water. 

Why does not the fire under the vessel warm the contents above o° C. 
until after all the ice is melted? Why does it afterwards raise the temperature 
of the water rapidly up to ioo° C. and no further? 

Because all the heat communicated to the ice was utilized in performing 
the interior work referred to in the preceding paragraph and therefore could 
not at the same time increase the temperature of the ice (solid water); but the 
heat afterwards communicated to the water did not do any interior work but. 
raised the temperature instead until the boiling point was reached. At the 
boiling point the water could no longer exist in a liquid state, because the ten- 
sion of its vapor at that temperature is greater than the atmospheric pressure 
and the continued application of heat, therefore, resulted in the vaporization 
of the water, all the heat now communicated doing " interior work" again in 
overcoming cohesion (55). 

313. Similar results follow the application of heat to other solids and 
liquids. 

Any given solid always melts at the same temperature if the pressure be 
the same. 

Any given liquid always boils at the same temperature, provided the 
pressure be the same. 

Hence any given fusible solid hastits own specific melting point (376); any 
given vaporizable liquid has its own specific boiling point (392); and any 
vaporizable solid, which does not melt before it vaporizes, always volatilizes 
at the same temperature. 

But different substances generally have different melting points, different 
congealing points (381), and different boiling points. 

314. Temperature. — The intensity of heat is called tempera- 
ture. It is measured by the expansion it produces in the vol- 
umes of bodies (320). 

The molecules of all matter are in continual motion, and 
all bodies have heat. Increased intensity of heat motion means 
a higher temperature, and slower molecular motion means a 
correspondingly lower temperature. 

315. The old theory of heat regarded heat as " imponder- 
able matter," or matter without weight. 

But there can be no matter without weight, for matter i( ^£^3g else but 
that which is weighable. 

It was thought that turning a solid into a liquid by the w I of heat was to 
add heat to the solid, the result of this union of two things I -r-ng a liquid; and 
that by adding more heat to the liquid a gas was produced. I.t was further said 



76 PHYSICS. 

that the gas could be turned into a liquid again by taking away heat from it, 
and that liquids were turned into solids in the same way. 

The strongest confirmation for this theory was the fact that when bodies 
are reduced in volume by pressure, heat is generated. It looked as if heat 
could be squeezed out of the matter. 

But the " sensible "or " active " heat which makes its appearance when 
the volume of a body is diminished by pressure is pre-existing energy mani- 
festing its presence by new phenomena. 

316. The Sun, which is the source of all the energy of the life of plants 
and animals, and of nearly all the energy employed in mechanics, is also the 
greatest source of heat. It is the first source of most of the available heat 
of the globe. The total heat emitted by the sun is two thousand one hundred 
and twenty-nine million times that which reaches our earth. The Jixed stars 
also send radiant heat to the earth. As our vast coal beds are formed from 
vegetable growths, they represent stored up potential energy derived from the 
sun. 

Heat is also stored up in the interior of the earth. 

317. Friction, percussion and compression produce heat. 

Fire may be produced by rubbing two pieces of wood against each other; 
savages produce fire in that manner. The composition on the end of matches 
ignites by comparatively light friction. If you rub a piece of metal against a 
stone it gets hot. A piece of steel held against a rovolving dry grindstone not 
only gets hot, but sends incandescent particles of steel flying from it. 

A piece of wrought iron may be hammered until red hot. A single blow 
explodes a mixture of potassium chlorate and sulphur, and the composition in 
a percussion cap. 

A piece of tinder fastened to the end of the piston of a strong glass syringe 
may be ignited by suddenly driving the piston into the tube; this result is 
caused by the great amount of heat liberated when the air is compressed. 

318. Chemism also produces heat. 

Whenever any two kinds of matter react upon each other chemically (319), 
hest is evolved. The amount of heat thus liberated is constant for any given 
reaction. Electricity is also generated by chemical action, and heat may be 
also produced by electricity. 

319. Combustion is chemical action, and is one of the main 
direct sources of heat available to man. 

But heat is liberated in very large amounts, even by chemical reactions, 
which are not accompanied by flame or light, as when diluted sulphuric acid 
and water of ammonia are mixed, or when lime is slacked by pouring water 
upon it. 

But the relatioHS of heat to chemism will be referred to again further on 
(514). 



77 



PHYSICS. 

CHAPTER XVI. 

THERMOMETRY. 

320. Temperature (314) is measured by instruments called 
thermometers. These are so constructed that the expansions 
and contractions caused by changes in the temperature can be 
easily seen and expressed. 

The substances most used aa indicators are mercury, alcohol, metal and 
air, all of which respond readily and sufficiently regularly to the changes in 
the velocity of heat vibration. 

321. The mercurial thermometer, which is so universally employed, is 
constructed as follows : 

It consists of a glass tube of extremely fine calibre — a capillary canal — 
expanded at its lower extremity into a bulb (fig. 83). The bulb and part of 
the tube are filled with pure mercury, after which 
the air is carefully expelled and the upper end of the 
tube closed. The instrument is then inserted into 
pounded ice, and the point at which the top of the 
mercury then stands is marked. The next step is 
to suspend the tube in the steam rising from pure 
boiling water in such a way that it is completely 
surrounded by it. This causes the mercury to rise 
in the tube until it reaches a certain point at which 
it stops and remains fixed. This point is also 
marked. The interval between these two points is 
now graduated into 100, 180, or 80 equal spaces (or 
intervals, called degrees) according to whether the 
scale is to be that of Celsius, Fahrenheit, or Reau- 
mour. 

The scale of degrees is, therefore, based upon 
the melting point and boiling point of water. 

322. The Centigrade Thermome- 
ter. — The thermometer scale devised by 
Celsius (Fig. 85) is deservedly esteemed 
the most simple, rational, and worthy of 
universal adoption. It is called the centi- 
grade thermometer because the interval be- 
tween the melting and boiling points of water is divided into 
one hundred degrees (or equal spaces). The scientific simplicity 



-212 

-192 

-172 

-152 

-132 

-112 

-92 

-72 

-52 

■32 



Figs. 83, 84, 85. 



IOC' 
80 
60 
'0 
20 




78 PHYSICS. 

of this thermometer as compared with others has led to its almost 
universal employment in science. 

Although Fahrenheit's thermometer (325) is the one in general use for 
ordinary purposes in the United States, the centigrade thermometer is used 
by our chemists and in the Pharmacopoeia. 

323. On the centigrade scale the freezing point (or, rather, 
the melting point) of water is denominated zero (= o° ), and 
the boiling point consequently + ioo°. The degrees above zero 
are the positive (+) degrees, and those below it, which are made 
of equal length on the scale, are called negative ( — ) degrees. 

324. On Reaumour y s scale the freezing point is also zero, or 
o°, but the boiling point is + 8o°. Thus four degrees R. are 
equal to five degrees C, and 

C.° : 100 :: R.° : 8o°. 

In order, therefore, to convert any number of degrees R. to the corres- 
ponding number of degrees C, multiply by \; and to convert from C. to R., 
multiply by f . 

325. Fahrenheit's thermometer (Fig. 84), which is almost 
exclusively used by the people of the United States and Great 
Britain, has the freezing point marked + 32 , and the interval 
between this point and that at which water boils is divided into 
180 equal spaces (instead of 100 as in the centigrade thermome- 
ter). Thus + 32 F. equals + o° C, and ioo° C. equals (32 4- 
180 = ) + 212 F. Nine degrees on Fahrenheit's scale occupy 
the same distance, relatively, as five degrees on the centigrade 
scale. 

But to convert F.° into C.° it will not answer to multiply the number of 
degrees F. by 5-9 until after 32 has been deducted from the number, for C.°: 
100: : (F.° — 32) : 180, or gC.= 5 (F — 32); and in converting C.° into F.° the 
number of degrees C. must first be multiplied by 9-5, and then 32 added to the 
product. 

The rule, then, for reducing thermometric degrees from C. to F. is 

Multiply by q 5 and add 32, 
and the rule for reducing Fahrenheit's degrees to Centigrade is 

Deduct 32 and jnultiply the remainder by j-o. 

326. Mercury thermometers are made to indicate temperatures from 
— 30 F. to -f- 6oo° F. At very high temperatures, however, the scales are liable 
to vary from each other somewhat, for want of an unexceptionable natural 



physics. 79 



ft 



standard by which they may be corrected. When sealed at the top a good 
mercury thermometer can not be made to indicate temperatures above +580 
F., as the mercury may boil above that point. But the most accurate 
instrument indicates correctly only degrees between — 35 C. and a little 
over -f- 200 C. 

327. As the freezing point of alcohol is much lower 
than the freezing point of mercury alcohol thermometers 
(or " spirit thermometers") are used for measuring very 
low temperatures. 

The alcohol in the tube is usually colored red so that the readings 
may te easier. 

328. Pyrometers are metallic thermometers, or instruments by 
which temperature is measured by the linear expansion of bars of 
metals. They are of various forms, but their indications are very 
uncertain. 

329. Air thermometers are very sensitive, and the most reliable 
thermometer known is Regnault's air thermometer; but it is too com- 
plicated to be described in such a book as this, and is used-only for 
special scientific determinations and comparisons. 

330. Laboratory thermometers used for measuring high 
temperatures of liquids, in chemical and pharmaceutical 
work, are constructed somewhat differently from those 
intended for ordinary purposes. They are long and slen- 
der, of exceedingly fine bore, and have very small bulbs 
(Fig. 86). The advantages gained by these conditions are 
that the divisions on their scales are larger and, therefore, Fig. 86. 
more accurate, and the instrument readily attains the temper- 
ature of any liquid in which it is plunged, without materially 
affecting it. Small thermometers — slender tubes of small inter- 
nal diameter — are, as a rule, more accurate than larger ones. 



80 PHYSICS. 

CHAPTER XVII. 

ABSOLUTE HEAT AND SPECIFIC HEAT. 

331. Absolute Heat and Specific Heat. — It has been 

shown (321) that the arbitrary degrees of temperature indicated 
by all thermometers are based upon the constant temperatures 
of boiling water and melting ice under the pressure of one 
atmosphere. 

But these degrees do not tell us how much heat a body con- 
tains. 

Thus the zero point does not indicate absence of heat, nor does a tem- 
perature of 100 indicate that a body at that temperature contains 100 times 
as much heat as it contains when at i°, nor that boiling water is twice as hot 
as water at 50°. 

Bodies have been cooled to — 220° F. without reaching the absolute zero 

(332). 

332. Absolute Temperature. — Air and other gases ex- 
pand uniformly with equal increments of temperature (364). 
Air thus expands to the extent of -^-3 of its volume for every 
added degree according to the centigrade scale. Therefore air 
of _|_ 273 C. occupies twice as much space as is occupied by the 
same amount (by weight) of air at o° C. Below zero the vol- 
ume of the air is diminished in the same ratio, so that if it 
be cooled to — 273 C. its volume must theoretically be reduced 
to nothing provided it remains in a gaseous state; but the air 
becomes a solid long before that temperature is reached, and it 
would then no longer obey the law of Charles (333). 

It is assumed, however, from the foregoing, and for other 
more conclusive reasons, that at — 273° C. all bodies become 
entirely devoid of heat. That point is, therefore, called absolute 
zero, and temperature counted upward from absolute zero is 
called absolute temperature. On this scale all temperatures would 
be positive (323.) 

333. The law of Charles is that the volume of a given 
mass (7) of gas at constant pressure is directly proportional to 
its absolute temperature. 



PHYSICS. 8l 

334. The Specific heat of a body is the ratio of its capac- 
ity for heat as compared with that of an equal volume of water. 

As water is the standard comparison the specific heat of water is of course 
1, and the specific heats of the other bodies are expressed in water units, 
just as specific weights are also expressed in water units. 

335. Thermal Units, or heat units. — The amount of heat 
necessary to raise the temperature of one kilogram of water one 
degree C. is called the unit of heat, or thermal unit. 

It follows that the number of thermal units necessary to raise the tem- 
perature of any given body one degree expresses the specific heat of that body. 
(Heat units are also sometimes called calorics.) 

336. The temperatures of equal masses of different sub- 
stances are not raised equally by equal amounts of heat. 

If equal weights of mercury, alcohol and water are exposed to the same 
heat, the mercury will rise 30°, while the alcohol rises 2° and the water i°. 
In other words, it requires 30 times as much heat to raise the temperature of 
water one degree as it takes to raise the temperature of the same quantity of 
mercury one degree ; and it takes twice as much heat to raise the temperature 
of a kilogram of water from o° to i° C. as is required to raise the temperature 
of a kilogram of alcohol from zero to i° C. 

337. But the specific heat of all solids and liquids, and of 
most of the gases, increases slightly with the temperature. 

Thus water at o J C. has the specific heat 1 ; water at 40 C, 1.0013 ; at 
8o c , 1.0035. 

Liquids usually have a higher specific heat than solids and gases. The 
specific heat of water is almost double that of ice, and a little more than twice 
the specific heat of steam. 

338. Water possesses a greater capacity for heat than any other sub- 
stance except hydrogen. 

It requires more heat to warm it, and gives out more heat in cooling 
through a given range of temperature. The same quantity of heat that raises 
the temperature of one kilogram of water from o' C. to ioo° C. heats one 
kilogram of iron from o° to 8oo° or 900 C, or above red heat. 

339. The heat lost in cooling is precisely the same amount 
as is required to raise the same body through the same number 
of degrees. 

Therefore, when equal weights of different substances are heated to the 
same temperature and then placed on ice, the amount of ice melted will be in 
proportion to the number of thermal units they contain. If a given weight of 



62 PHYSICS. 

boiling water will melt one pound of ice, an equal weight of sulphur of ioo° C. 
will melt ^, iron ^, and mercury ■£$ of a pound of ice. 

340. If one kilogram of water at ioo° C. be mixed with the 
same quantity of water at o° C, the temperature of the mixture 
will be Aoo|>oil = 5 o° C. 

Thus the heat lost by the boiling water is precisely the same amount as 
that gained by the ice water. But this simple result does not follow when 
different substances are mixed. 

341. The high specific heat of water explains why the vicin- 
ity of large bodies of water produces such a decided effect in 
moderating climate. 

Lake Michigan makes the summers of Chicago cooler, and its winters 
warmer. 



CHAPTER XVIII, 



DISTRIBUTION OF HEAT. 



342. Distribution of Heat. — Heat may be conveyed from 
one body to another not only when they are in contact, but also 
when there is a distance between them. In the former case the 
heat is transmitted either by conductio?i or by convection; in the 
latter by radiation. 

343. Conduction. — If a piece of metal be heated at one 
point, we may readily observe that the heat gradually spreads 
throughout the whole mass. The same transmission of heat 
takes place when two bodies of different temperatures are 
brought into intimate contact with each other; the temperature 
of the colder body increases, while that of the warmer decreases, 
until both have attained the same degree (382). 

This is called the conduction of heat, and the heat motion is 
communicated from molecule to molecule. 

344. The rapidity with which heat is conducted from mole- 



PHYSICS. 8$ 

cule to molecule varies in different substances; but the ten- 
dency to an equalization of temperature is universal. Any body 
having a higher temperature than surrounding bodies, will 
sooner or later impart to them some of its heat, until all have 
attained the same rate of molecular vibration. 

345. The power of any body to conduct heat is generally 
proportional to its density. Metals and stones are good con- 
ductors of heat; they quickly become heated, and as quickly 
cooled, and are commonly designated as cold bodies. Porous 
substances, like wood, wool, cotton, are poor conductors of heat; 
they are less readily made hot, retain their temperature longer 
than the good conductors of heat, and are called warm bodies. 

Liquids and gases are almost non-conductors. Feathers, fur, 
and wool owe their non-conducting properties largely to the 
air confined between their fibres and meshes. 

346. The conducting power of a body may be judged of to some extent 
by the sense of touch. In cold weather stones and metals feel colder to the 
touch than glass, resin, wood, water or air, and in the summer the same 
stones and metals feel hotter than the other objects. Oil cloth on the floor is 
colder in winter and warmer in summer than a woolen carpet. 

347. Cooking utensils, such as kettles, pans, etc., and the vessels used 
by pharmacists and chemists for heating liquids, are made of good conduc- 
tors of heat, such as metals, as far as practicable. Earthen ware, porcelain 
and glass are used for these purposes only, because many substances attack 
metals and are themselves affected by contact with metals. 

Silver has a very high thermal conductivity, and copper is also an excel- 
lent conductor; iron is far inferior to either. 

348. Poor conductors are extremely valuable, both as a 
means of preventing the escape of heat, and to exclude heat. 

Thus, if a vessel containing a hot liquid or vegetables put in boiling water, 
be covered and placed in a wooden box lined with felt, and the box tightly 
closed, the high temperature will be retained for many hours. Shrubs and 
plants are wrapped in straw to prevent the escape of their heat. Snow pro- 
tects vegetation from the extreme cold of winter. Furnaces would be 
useless without the fire brick which, being made of non-conducting material, 
retains the heat. Clothing keeps the heat of our bodies in and keeps the cold 
of the air out. Animals in cold regions are protected by their fur and down. 

349. Convection is the transmission of heat vibration by 
the motion of masses of molecules in currents. 



84 PHYSICS. 

Convection, therefore, occurs only in liquids and gases, in which currents 
are possible. It depends upon gravitation. Hot or warm liquids and gases 
are lighter or less dense than colder liquids or gases; and lighter fluids rise to 
the top while the denser fluids sink to the bottom. If, therefore, heat is 
applied under a kettleful of water, that portion of the water, which is first 
heated will rise to the surface, while other portions of water take its place, 
and currents are thus established in the liquid, which materially aid in diffus- 
ing the heat through the whole mass. A fire in a grate heats the air above it 
and the heated air rises through the chimney, while a new supply of air takes 
its place creating a draft. 

350. In all cases where currents are thus established in fluids by the 
application of heat at the bottom of the liquid or gas, the currents are in opposite 
directions, the heated fluids rising upward while the cooler portions flow in 
downward currents. 

The lower strata of air are warmed by the earth and then rise, the colder 
strata descending to take their place. Moreover, as the earth is not heated 
equally in all places, horizontal currents are established in opposite directions, 
which we call winds. 

351. Ventilation is intimately connected with the convec- 
tion of heat and the opposite currents established by it. Venti- 
lation is the removal of vitiated air from rooms, shops and other, 
confined spaces, and the supplying of fresh air to take its place 
the object being to maintain the atmosphere in a state of purity. 

In apartments occupied by men or by animals the air becomes vitiated by 
respiration, the oxygen of the air being consumed, carbon dioxide taking its 
place. An adult man inhales about fourteen cubic feet of air per hour; but it 
is not enough that the amount of air in the apartment be sufficient for the 
inhalation of fourteen cubic feet per hour. The air inhaled must be pure at 
any and all times, and this requires a constant supply of fresh air and a con- 
stant escape of the vitiated air. 

The combustion of oil or gas for illumination also consumes oxygen, and 
thus vitiates the atmosphere of a room. 

When a window is opened to produce a change of air, it should be opened 
at the top, because the cold, fresh air entering near the ceiling diffuses through 
the whole room, while the foul, airbeing warm, escapes. 

The air in a room is warmest at the ceiling. Hence, in a drug store, sub- 
stances which are liable to be injured by the higher temperature in the upper 
strata of the atmosphere of the room should not be kept on the top shelves. 

352. Radiation of heat. — The heat which is diffused 
through space from the sun reaches the earth by radiation. 



PHYSICS. 85 

353. In order to be able to explain or understand how heat and light 
can be received by us from the sun, it is necessary to assume that the space 
which separates the terrestrial atmosphere from the sun can not be empty, for 
motion can not be communicated by nothing or through empty space. It is, 
therefore, assumed that there is a medium, which has received the name of 
ether, capable of communicating motion, and occupying all of the otherwise 
unoccupied space in the universe. Ether is accordingly supposed to pene" 
trate between all molecules of matter. Ether is not matter; it can not be 
weighed nor measured. It can not be seen, heard, felt, tasted nor smelled. 
But its existence is assumed because the phenomena occurring in nature can 
not be accounted for on any other supposition, while they are explainable on 
the hypothesis that an ethereal medium exists which is capable of transmit- 
ting motion. These phenomena occur in just such a manner as they must 
occur if all space were filled with such a medium. 

354. Sound, light and heat are transmitted through the medium of ether, 
and are, therefore, referred to as forms of radiant energy. They are commu- 
nicated by a wave-like, vibratory motion, and this theory of wave-action is 
called the undulatory theory. All the phenomena of light and of radiant heat 
show a remarkable analogy. 

355. Heat radiates in straight lines in all directions, and the 
intensity of radiant heat is inversely as the square of the dis- 
tance from its source and proportional to the temperature of 
that source. 

356. Different bodies vary greatly in the power of emitting 
radiant heat. Lamp black has the highest radiating power 
known, and polished metals are the poorest radiators of heat. 
A bright silver tea-pot filled with hot liquid retains its temper- 
ature longer than one of earthenware. 

Steam pipes for heating buildings should be kept bright until they reach 
the rooms where the heat is to be diffused; there they should be coated with 
lamp black to increase their radiating power. 

357. Heat is reflected by all substances which are good 
reflectors of light. Thermal rays are also refracted like rays of 
light, but the thermal rays are of different refrangibility and 
wave length (412). 

Transparent bodies generally transmit heat as well as light 
from the sun, but they do not transmit equally the heat rays 
from artificial sources. 



86 PHYSICS. 

The heat from the sun warms the room through the window-glass, but 
the same thickness of glass intercepts the heat from the fire-place. 

Different substances transmit heat unequally, and absorb heat 
unequally. Heat rays which are absorbed increase the temper- 
ature of the bodies which absorb them; rays which are trans- 
mitted or reflected do not warm them. 



CHAPTER XIX. 

THE EXPANSION OF BODIES BY HEAT. 

358. The first and universal effect of heat upon most bodies 
is to increase their volume (309). 

This expansion of a body by heat is the result of a widening of the dis- 
tances between the molecules of the body. Heat motion increases the iuter- 
molecular spaces, and thus overcomes cohesion. 

359. Numerous easy experiments might be described here to prove that 
heat expands matter; but you can doubtless invent some yourself, and I will, 
therefore, only refer to a few familiar examples. 

The mercury or alcohol in the thermometer (320) expands with an increase 
of temperature, and contracts with a reduction of it. 

The rails of a railroad are of necessity laid in such a manner that their 
ends are not in actual contact even in hot summer weather; if they were laid 
without any space between their ends they would expand under the influence 
of the heat from the sun so as to bend out of shape. In cold weather there is 
considerable space between the ends of the rails. 

A metal ball or cylinder which, when cold, passes through but nearly 
fills a metal ring will not pass through if heated. 

If you fill a tin cup to the brim with cold water and set it on a hot stove 
the water will run over when it becomes warm. 

If a glass stopper has been inserted into the neck of a bottle so tightly 
that it can not be removed in the usual way, you can loosen it by warming the 
neck of the bottle, for as the neck of the bottle expands the stopper will, of 
course, no longer fill it so tightly. 



PHYSICS. 87 

[In doing this remember that only the neck of the bottle is to be expanded 
and not the stopper, for if you heat the neck so long that the heat is trans- 
mitted to the stopper, too, both will expand. Moreover, take care that the 
heat be applied cautiously so that the glass may not break (365). The neck 
of the bottle may be heated by friction (317), which is easily applied by pull- 
ing back and forth a cord tightly wound around it. 

360. Force of Expansion and Contraction. — Water 
expands for each degree F. with a force equal to ninety pounds 
to the square inch; i. e., it would require that amount of force 
to resist its expansion when its temperature is increased one 
degree. 

To compress boiling water back to its volume at the freezing point would 
require a pressure of one thousand atmospheres, or a layer of mercury almost 
half a mile thick. 

361. The expansion of solids and liquids by heat is unequal. 
Gases, however, expand equally and uniformly (364); under 

equal pressure their volumes increase in the same ratio with 
equal increments of temperature, and at equal temperature 
their volumes are inversely as the pressure which they sustain 
(Boyle, Mariotte and Charles). 

Gases, when their temperature is raised, expand more than 
solids and liquids. 

362. Linear expansion (or linear dilatation) is expansion in one 
direction only, as when a rod or an iron rail is lengthened by an 
increase of temperature. 

363. Cubical expansion (or cubical dilatation) is expansion of 
volume. Solids, liquids and gases are all subject to cubical 
expansion and contraction as their temperature increases or 
decreases. 

364. Co-efficients of Expansion. — By "co-efficient of 
expansion " is meant the number which expresses the measure 
of the expansion of a body when its temperature is raised one 
degree. The ratio of expansion for gaseous bodies is 0.003663 
(or -g^-j) of their bulk for each degree C, or 0.002037 (or ^V.-g) 
for each degree F., above the freezing point of water. This 
means that the bulk of a gas is increased by 0.003663 (or -^-j) 



8S PHYSICS. 

when its temperature is increased one degree by the centigrade 
thermometer, and by 0.002037 (or j^ i7 ) when it is raised one 
degree by Fahrenheit's scale. 

In the case of solids and liquids the ratio of expansion 
increases as the temperature rises. 

365. Unequal expansion by heat often results in the fracture 
of brittle solids', that danger is greater the thicker the solid is, 
and greatest when the thickness is unequal. 

Cast iron and glass, when suddenly heated, are liable to crack, because 
the side to which the heat is applied expands more rapidly than the other 
side. Sudden cooling has the same effect by causing unequal contraction. 
Thick vessels of glass, porcelain, wedgewood ware, etc., like graduates, mor- 
tars and bottles, and especially vessels of unequal thickness, are frequently 
cracked by carelessly heating or cooling them suddenly. Do not pour hot 
liquids in cold glass or eathenware vessels nor cold water in the same vessels 
when hot, and do not put a hot dish on a cold surface nor a cold one on a hot 
surface. 

366. Expansion of Water. — Water forms the only excep- 
tion to the rule that bodies expand whenever their temperature 
is increased, and contract whenever the temperature is lowered, 
for the maximum density of water is attained at 4° C, (39. 2 F.), 
and it expands both below and above that temperature. 

If you fill two strong bottles completely with ice water, cork them tightly 
and tie the corks securely with wire, and then let one of them be exposed to 
such cold that the water will freeze, and warm the other, both will burst, 
because the water in both bottles will expand. 

367. Were it for the fact that ice is lighter than the water upon which it 
is formed, all those portions of the globe where the temperature in the winter 
season falls below the freezing point of water would be uninhabitable; for 
the solid water (ice) were heavier than liquid water, the ice would sink as fast 
as it is formed, and all the rest of the water would be gradually frozen to ice, 
until all the lakes and rivers were frozen solid from bottom to surface. The 
heat of summer would then be insufficient to melt the ice. 

But, as water is heavier at 4 C. than when it has any other temperature f 
the water at the surface of the lakes and rivers, as soon as it is cooled down 
to + 4 C, sinks to the bottom, and the warmer water rises to take its place and 
to be in turn cooled to the same temperature, until the entire body of water 
has a temperature of + 4 C. before any ice is formed, after which the ice 
formed on the.surface, being lighter than the water below, remains floating. 



PHYSICS. 89 

At the moment of freezing, water suddenly increases in volume about ten 
per cent. 

368. At its maximum density (+ 4 C. = 39°. 2 F.), water 
is 773 times as heavy (or dense) as air of o° C; but water at 15 
C. is 819 times as heavy as air of the same temperature. 

Thus water and air expand very unequally with the increase of their 
temperatures. 

369. Water freezes at o° C. (32 F.), or under certain con- 
ditions several degrees below that temperature. 

If you boil some water (to expel the air from it), put it in a bucket or other 
vessel and let it stand perfectly at rest, with a thermometer hanging down into 
it, allowing the water to cool slowly, the water may remain liquid until the 
thermometer indicates — 3 or — 4 C. But if you then suddenly stir the 
water around with the thermometer it will freeze at once, and its temperature 
will then at the same time rise to o°, because the latent heat which the water 
absorbed in its expansion below o° is liberated as it contracts to form ice at o°. 

370. The expansion which takes place when water freezes to ice at zero 
(C), bursts porous stones, and great rocks may be split by boring holes in 
them, filling these with water, plugging the opening tightly and allowing the 
water to freeze. 

371. Ice contracts more than any other solid upon being cooled. Under 
strong pressure ice may be rendered liquid even at — 18° C. 

372. The melting point of ice is uniformly o° C. under the ordinary 
atmospheric pressure. In thus passing from the solid to the liquid state, 
water takes up an amount of heat sufficient to raise the temperature of a like 
quantity of water from o° C. to 79 C. 

373. When heated above 4 C. water continues to expand 
until it reaches the boiling point, which is at ioo° C. (212 F.) 
at the ordinary atmospheric pressure. The boiling point is 
lower under less pressure, and higher under greater pressure. 

Under the pressure of two atmospheres the boiling point of water is at 
+ 121 C, and under three atmospheres at +134° C. But on high mountains, 
where the barometric (or atmospheric) pressure is less (285), the boiling point 
of water is correspondingly lower, so that the altitudes of mountains may be 
determined by the temperature at which water boils on their summits. 

374. Water evaporates (390) at all temperatures. 
Even ice gives off vapor. 

This tendency of water to form vapor is its tension (77) which increases as 
the temperature increases, and can be accurately measured. 



90 PHYSICS. 

CHAPTER XX. 

RELATION OF TEMPERATURE TO THE THREE STATES OF AGGREGA- 
TION OF MATTER. 

375. As the several states of aggregation of matter (68) 
depend greatly upon their temperature (314) we may look upon 
solids as matter in a frozen condition, liquids as melted matter, 
and gases as vaporized matter. Different kinds of matter con- 
geal or freeze to a solid mass at different temperatures ; they 
fuse or melt at different temperatures ; and they boil or vaporize 
at different temperatures, according to their kind. 

Hydrogen does not exist at ordinary temperatures except in the gaseous 
state ; indeed it requires great cold and pressure to condense it to a liquid, and 
that liquid boils at the low temperature of — 210 C. under a pressure equal to 
190'' atmospheres, or at — 140 ° C. under 650 atmospheres. 

Alcohol is a liquid at ordinary temperatures, and does not freeze solid 
until at — 130° C; but it boils at about 78 C. (172°. 4 F.). 

Oil of Theobroma or "Cacao Butter" is at the ordinary temperature a 
solid; it melts to a liquid by the warmth of your hand, and is frozen solid 
again a little below that temperature. 

But gold is frozen solid at a temperature exceeding 1,000 degrees above 
zero, according to the centigrade thermometer (322), or over 1,800 degrees by 
Fahrenheit's scale. 

376. Many solids can be changed into liquids by heat. 
Their liquefaction by heat is called fusion; solids which melt or 
fuse when heated are said to be fusible, and the particular degree 
of temperature (313) at which a solid undergoes fusion is called 
its i?ielting-point or fusing-point. 

Metals, resins, fats, and many other solids are fusible. 

But there are also many infusible solids, as starch, gums, wood, carbon, 
clay, etc. 

Ores which are either infusible, or melt only with extreme difficulty at 
extremely high temperatures, are called refractory ores. 

377- Some solids when subjected to high heat " volatilize 
without fusion," or pass into a state of vapor without melting. 

Arsenous oxide, benzoic acid, gallic acid, calomel, and many other solid 
substances volatilize and sublime (405) without fusing. 

Vaporizable solids are said to be volatile. 



PHYSICS. 91 

378. Softening by heat without fusion. — Many substances 
soften materially much below their melting point. 

Ointments, cerates and plasters, and the fatty substances and resins from 
which they are made, generally have that property. 

Other substances which do not fuse at all are, nevertheless, rendered soft, 
plastic, or pasty when heated, becoming hard again on cooling, as is the case 
with many dry solid extracts. 

379. There are many solids which are both fusible and 
volatilizable; but there are other solids, which, although fusible, 
can not be converted into vapor. 

380. Fixed substances are those which can not, by ordi- 
nary means, be made to* assume the gaseous state. 

If a sufficiently intense heat could be applied, it is probable that all sub- 
stances could be converted into vapor; but bodies which are not volatilized at 
the high temperatures which can be produced by the means at our command, 
are said to be fixed. Fixed alkalies are the non-volatile hydrates of potassium 
and sodium, but ammonia is a volatile alkali. Most mineral substances are 
fixed, as the metals, etc. 

381. All liquids and gases can be turned into solids by cold 
or by pressure, or by both; but not all liquids can be converted 
into vapor; nor can all solids be turned into fluids. 

382 Bodies in a state of fusion reassume the solid state 
after the application of heat has been discontinued and the 
usual equalization of temperature has taken place (343)' 

Certain substances, which solidify at high temperatures, liberate so much 
heat at the moment of solidification (or congelation) that they become glow.ng 
throughout their mass. 

The temperature at which liquids solidify is called their congealing point 
ox freezing point. Theoretically, this point is nearly identical with, or but 
slightly below the degree at which the solid became liquid; but it frequently 
happens that liquids retain their liquid state below that point, in which case 
they give off their latent heat all at once, when solidification at last takes 
place (369). 

383. Expansion at the Moment of Solidification. — That water expands with 
great force at the point of freezing we have already noted (369). Water pipes 
burst in cold weather if the water in them is allowed to freeze. But some 
metals, too, expand when they solidify, as cast iron, tin, zinc, bismuth, anti- 
mony and some of their alloys. Such metals and alloys are used to make 
casts because they fill the molds so perfectly by their expansion that the casts 
become very sharp and perfect. 



9 2 



PHYSICS. 



Most substances, however, contract in the act of solidifying; thus coins 
of silver, gold and copper can not be cast in molds, but must be stamped. 

384. A curious phenomenon connected with this subject is the fact that 
mixtures of solids produced by fusion, such as alloys of metals and fatty mix- 
tures, frequently have lower fusing points than either of the constituents of 
the mixture. Thus Rose's alloy, which consists of 4 parts of bismuth, I of 
lead, and I of tin, fuses at 94 C. (201 F.). A mixture of equal parts of 
potassium carbonate and sodium carbonate melts at a lower temperature than 
either salt separately. 

385. That solids absorb heat (and render it latent) in passing into the 
liquid state is well illustrated in the solution of solids which take up so large 
an amount of heat as to greatly lower the temperature of the solvent. 

Whenever a solid is dissolved in any liquid, the solid must take up latent 
heat in passing into the liquid state, but some solids take up more heat than 
others. 

You may easily learn this by dissolving readily soluble salts in just 
enough water to accomplish their solution, and best by dissolving more than 
one salt in the same water; provided, of course, the salts used are such as do 
not decompose each other. Thus if you dissolve equal parts of ammonium 
chloride and potassium nitrate in barely sufficient water, you will observe 
that the temperature of the liquid falls rapidly, and the vessel as well as the 
solution becomes very cold. That is because the salts could not dissolve or 
become liquid without taking up heat, and they took this heat from the sur- 
rounding bodies — from the water in which they were dissolved, and then from 
the vessel in which the solution was performed, and from the contiguous air, 
and when you grasped the vessel in your hand heat was abstracted from 
your hand, producing the sensation of cold. 

386. Freezing viixtures are made on this principle (385). Some mixtures 
of readily soluble salts with twice their weight of water depress the tempera- 
ture about 20 degrees centigrade. A mixture of three parts crystallized cal- 
cium chloride with two parts of snow will cause mercury to freeze. The 
freezing mixture used in ice cream freezers consists of about two parts of 
snow and one part of common salt: this will produce a temperature of about 
— 20 C. ( — 4 F.). Another effective freezing mixture consists of five parts 
hydrochloric acid and eight parts crystallized sodium sulphate. 

387. There are some substances which change from the solid to the 
liquid state or vice versa at common room-temperatures, as glacial acetic acid, 
volatile oil of anise, oil of rose, etc. They are frozen solid in a cold room, 
and melt into liquids again in a warm room. 

388. Numerous liquids are vaporizable by heat, and if the 
temperature at which they vaporize is not comparatively high 
the liquids are said to be volatile . 



PHYSICS. 



93 



Water, alcohol, ether, benzin, gasolin, are vaporizable, and all of them, 
except water, are volatile liquids. 

389. Substances which are liquid only under pressure vapor- 
ize at once upon the removal of the pressure. 

Ammonia, carbonic oxide, nitrous oxide, and several other gases are now 
compressed into a liquid state in cylinders. 

390. Evaporation. — The slow conversion of bodies into 
vapor may take place at any temperature. Thus, we have seen 
(374) that water vapor will pass off even from ice. 

Volatile solids evaporate at ordinary temperatures, as, for instance, 
camphor, iodine and chloral. Water evaporates constantly. 

Evaporation under the ordinary conditions of temperature and pressure 
is sometimes called spontaneous evaporation. 

391. The Rate of Evaporation increases with the tempera- 
ture because heat increases the tension of vapors. It also varies 
inversely with the pressure to which the evaporating liquid is 
subject, because greater pressure involves greater resistance to 
the vapor tension. Evaporation is far more rapid in a vacuum 
than in air. 

The rate of evaporation also depends upon the amount of 
vapor of the same kind already contained in the air into which 
the evaporation is going on. It is greatest when the air is free 
from vapor, and ceases when the air becomes saturated. Hence, 
if the air be changed frequently or continually, so that it can 
not become charged with too great a proportion of vapor, the 
evaporation will proceed more rapidly than if the air is sta- 
tionary, and thus becomes saturated, or nearly so. 

In a breeze the evaporation of water from the surface of the 
earth is much more rapid than when the air is still. 

As evaporation can take place only at the surface of a liquid, 
the rate of evaporation also depends directly upon the extent of 
surface exposed. 

392. The temperature beyond which a liquid can not con- 
tinue in a liquid condition without increased pressure is its 
boiling point. 

In other words, the boiling point of a liquid is the temperature at which 
it boils or becomes rapidly converted into vapor. A comparatively rapid 



94 PHYSICS. 

conversion of a solid or liquid into vapor at the boiling point is called vapori- 
zation. 

Boiling is often called ebullition. 

393- The boiling point of a liquid depends upon the nature 
of the liquid and upon the pressure of the superimposed air. 

Carbon dioxide boils at — 42°.44 C. ( — io8°.4 F.); stronger ether at yf C. 
(98°. 6 F.); alcohol at 78 C. (i72°.4 F.); water at ioo° C. (212 F.); mercury at 
350° C. (662° F.); zinc at 1040° C. (1904 F.). 

Salts and other substances held in solution in the liquids generally raise the 
boiling points of the latter. Liquids of great density usually have higher boiling 
points than lighter liquids, but there are many notable exceptions. If you 
compare the densities and boiling points of alcohol and ether, you will find 
that the rule holds good; but if you compare alcohol and chloroform, you 
will observe that although chloroform is more than one and three-fourths 
times as heavy as alcohol, it boils at about 61 3 C, while alcohol does not boil 
until 78° C. 

394. Saturated solutions of salts are often used to fix the 
degree of temperature applied to vessels and their contents in 
laboratory operations, for saturated solutions have fixed boiling 
points. 

Thus a saturated solution of common salt boils at io8°.4 C. (227 F.); 
one of potassium nitrate at 115°. 9 C. (240° F.); of calcium chloride at 179°. 5 
C (354° F.). 

But the water vapor formed when these solutions boil does not retain the 
high temperature of their boiling points. 

395. Boiling points vary with the pressure . — The vapor in its 
formation and continued existence must overcome all pressure 
from without which tends to condense it. As already stated 
the boiling point of a liquid is that temperature at which the 
tension of its vapor is greater than the pressure which it sus- 
tains. 

The measure of the atmospheric pressure must, therefore, be considered 
in the determination and expression of boiling points. When we speak of 
fixed boiling points, then, the boiling points under a pressure of one atmos- 
phere (284) are the boiling points referred to. 

At the level of the sea, water boils at ioo° C. (212° F.); on Mount Blanc 
it boils at 84 C. (i83°.2 F.); and in a " Papin's digester/' which is a strong, 
hermetically closed metallic vessel, the temperature of water may be raised 
to a very high degree without causing it to boil. In a steam boiler the water 
may attain a temperature of over 200 C. 



PHYSICS. q„ 

396. The vapor formed from water boiling under normal 
pressure is of the same temperature as the boiling water, or 
ioo° C. (2 12 F.). Under pressure, as when the steam is con- 
fined in boilers, pipes, coils, steam jackets, etc., the temperature 
of the steam increases with the pressure. 

But steam may be heated after it has been produced; it may- 
be passed through pipes into a furnace and there heated to a 
very high temperature. It is then called superheated steam, or 
dry steam . 

397. In a vacuum water boils at the ordinary temperatures. 
If a vessel of water of about 30 C. be placed in a glass bell and the bell 

then exhausted by means of an air pump, the liquid begins to boil after a few 
strokes; but the ebullition soon ceases on account of the pressure produced 
by the vapor which takes the place of the abstracted air. As soon as this 
vapor is pumped out, ebullition again sets in. 

If a long-necked flask of uniformly thin glass be half filled with water, the 
water boiled a few minutes so that the air might be expelled and replaced by 
water vapor, and the flask then removed from the source of heat, and promptly 
and tightly corked, the ebullition at once subsides; but if this flask be now 
immersed in cold water up to the neck, the contents will again boil briskly. 
This is because the vapor contained in the upper part of the flask is condensed 
by the cold so that a vacuum is produced, thus removing the pressure and 
greatly lowering the boiling point. 

398. When a mixture of several liquids of different boiling 
points is heated, it boils at a temperature somewhat above the 
boiling point of the most volatile constituent of the mixture. 

399. You have read that whenever a liquid passes into the 
gaseous state it takes up latent heat. 

This latent heat is called " the latent heat of vapors/' 

It requires 5^3 times as much time to convert a given amount of water into 
vapor as it takes to raise that water from o.°C. to ioo° C, the heat applied being . 
the same. Thus the latent heat of steam is 5^X100 = about 537 C. (967' F.). 

The same amount of heat that is necessary to evaporate one Gram of 
water is sufficient to raise the temperature of one Gram of water 537 degrees 
(centigrade), or to raise the temperature of 537 Grams of water one degree. 

The latent heat of alcohol vapor is about ic)0 .6C. (374°. 9 F.). That of 
ether vapor is about 72°.5 C. (i62°.8 F.). 

400. Cold from Evaporation. — The heat which is neces- 



96 PHYSICS. 

sary to convert a liquid into a vapor is taken from the surround- 
ing bodies. 

This fact is not noticed in vaporization by boiling because heat is con- 
stantly applied to the vessel containing the boiling liquid. But when evap- 
oration goes on at comparatively low temperatures the reduction of tempera- 
ture may be readily observed in the liquid itself, the vessel containing it, and 
the surrounding air. 

A rain shower cools the atmosphere because the water evaporates, and in 
doing so takes up heat from the air. 

If you put a small quantity of "stronger ether" in a watch crystal and 
let it evaporate at the temperature of the room, the ether will take up so much 
heat in its rapid evaporation that a drop of water on the other (convex) side of 
the watch crystal will be frozen to ice. 

When ether or alcohol evaporates from your hand a sensation of cold is 
produced. 

401. When vapors are deprived of their latent heat they are 
immediately condensed, or return to the liquid state. Vapor 
can not pass into the liquid state without liberating heat. 

Steam heating is based upon this fact. The latent heat of steam, 
together with most of its sensible heat, is available for heating purposes, as it 
must give off that heat in returning to the common temperature. 

Water is often heated to the boiling point in wooden tanks and in other 
vessels by forcing steam into it. 

402. Equal volumes of different liquids do not produce equal 
volumes of vapor. 

The expansion of water in passing into the state of vapor is greater than 
that of any other liquids. The value of steam as a source of mechanical 
power depends upon its expansive force. One cubic inch of water forms 
nearly one cubic foot of water vapor or steam. 

403. Distillation consists in vaporizing liquids in suitable 
vessels, called stills, connected with condensers and receivers in 
such a manner that thevapor can be reconverted into the liquid 
state and thus collected, the object of the process being to sep- 
arate volatile liquids from less volatile or fixed substances. 

404. Gases can be condensed into liquids, or even into the 
solid state, by cold, or pressure, or both. 

It was until 1878 supposed that air, oxygen, hydrogen and nitrogen were 
incompressible, incoercible, or permanent gases, i.e. , that these gases could 
not be condensed into either the liquid or the solid state. But all gases have 
now been liquefied and solidified. 



physics. 97 

405. Sublimation is the vaporization of solids and the con- 
densation of the vapor back to the solid state. 

406. Distillation and sublimation are applied to the puri- 
fication of substances resulting in the separation of volatile from 
non-volatile matters. 



CHAPTER XXI. 

TEMPERATURE AND HUMIDITY OF THE AIR. 

407. Saturation of air with vapor. — The air is said to be -saturated with 
vapor when it contains as much of it as it can hold. The quantity it can hold 
varies with the temperature, and with the kind of vapor. 

The atmosphere is said to be dry when it contains a relatively small quantity 
of moisture, and moist or damp when it contains a greater quantity. But the 
sensation of dryness or humidity does not correspond with the relative per- 
centage of moisture, for the air feels dry whenever it is capable of absorbing 
much more moisture than it contains, and moist whenever it approaches the 
dew point, which depends greatly upon temperature. A warm air which feels 
dry may contain much more moisture than a cold air that feels moist. 

AtO° C. the air can take up -^Xs P art °f lts weight of water vapor; but for 
every increase of n° C. its capacity for moisture is nearly doubled, so that at 
about ii° C. (52 F. ) it may contain j\g of its weight (or twice as much as at 
the freezing point), and at 22.22 or (72 F.) it can absorb -£$ (or three times 
as much as at zero C). 

408. The Dew Point. — If air that is saturated with moisture is cooled it 
can, of course, not retain all of that moisture; a portion of it must, therefore, 
be condensed ( ) and deposited as dew, and the temperature just below the 
saturation point, or that temperature at which the moisture contained in the 
air can not all remain in a state of vapor absorbed by the air, is call the dew 
point. Whenever the air is nearly saturated with moisture the dew point will 
therefore be only a little below the temperature of the atmosphere, and a slight 
fall of temperature will cause dew to be formed, for it contains more moisture 
than it would contain if saturated at the temperature of the dew point. The 



j8 PHYSICS. 

dew point is, therefore, lowei when the air contains less moisture, and higher 
when its humidity is greater. 

A vessel containing ice water will receive a deposit of dew upon the out- 
side as soon as its contents reach the dew point, which may be ascertained by 
a thermometer placed in the water. 

The relative humidity of air is its degree of approach to saturation. 

4C9. Clouds, fog, dew, rain, frost, snow and hail are the results of the 
condensation of atmospheric moisture into liquid and solid water. 

When a mass of warm, moist air strikes a colder mass of air, a portion of 
the water vapor contained in the warmer air is condensed to clouds of little 
bubbles of water filled with air; when these gather and collapse, rain comes. 
Fogs are only clouds formed near the surface of the earth. Condensed below 
the freezing point, it becomes white frost. Dew is deposited upon objects 
which are cooled after sundown. 

410. The temperature of the air is highest at the surface of the earth, 
and decreases as its height increases. At a certain altitude, then, the air is so 
cold that ice and snow never melt there. At the equator, the altitude of per- 
petual snow and ice is fifteen times as great as it is in a latitude of 75 , and 
two and one-half times as great as it is in a latitude of 75 ; but the differences 
depend not only upon latitude, but also somewhat upon local conditions. 

411. The temperature and moisture of the air have a direct influence 
upon health. Thus cold and ?noist weather is accompanied with a high death- 
rate from rheumatism, heart diseases, diphtheria and measles; cold weather, 
with a high death-rate from bronchitis, pneumonia and other diseases of the 
respiratory organs; cold and dry weather is attended with suicide and small- 
pox; hot weather brings with it a high death-rate from bowel complaints; and 
warm, moist weather exhibits greater mortality from scarlet and typhoid 
fevers. 



CHAPTER XXII. 



LIGHT. 



412. Light is that mode of motion which affects the optic 
nerve, or excites in us the sensation of vision. 

[Physically light is practically identical with radiant heat (314), the dif- 
ference being merely that of wave length.] 



PHYSIC 3. 



99 



413. The sources of light are : 1, mechanical action ; 
2, chemical action; 3, electricity; 4, phosphorescence; and 5, the 
heavenly bodies. 

Bodies that emit light by their own vibrations, as the sun, or 
the flame of a burning substance, are called luminous bodies. 
But trees, rocks, and other bodies which merely diffuse light 
received by them from other bodies are non-luminous or illumin- 
ated bodies ; they do not originate light. 

414. Transparent substances allow light to pass through 
their bodies so that objects can be seen through them. 

Water, air, glass, diamond ; clean, clear crystals of sodium carbonate, 
Rochelle salt, copper sulphate, ferrous sulphate, lead acetate, zinc sulphate, 
borax, alum, iron alum, etc., are transparent. 

415. Translucent bodies transmit light, but so imperfectly 
that objects on the opposite side can not be clearly seen through 
them. 

Ground glass, horn, waxed paper, a sheet of gelatin, shellac, etc., are 
translucent. 

416. Opaque bodies do not transmit light. By far the 
greater number of material objects are opaque. 

They cut off the light so that other objects can not be seen 
through them at all. 

417. Luminous rays. — Light radiates in all directions from 
every luminous point, and a single line of light is called a ray. 

418. Incandescence. — Any solid heated to nearly i,ooo° F., 
unless destroyed by such intense heat, emits, at that and higher 
temperatures, a dull red light, and is then said to be incandes- 
cent. 

The light of incandescent bodies varies with the degree of heat, being 
dull red, bright red, blue, orange, or white as the temperature rises; the light 
increasing in brilliancy with the intensity of the heat. 

419. Phosphorescence is a pale light, emitted in the dark, 
without any heat, as the light flashing from fire-flies, the green- 
ish light sometimes seen in the wake of a ship at sea, or that 
exhibited by rotten wood, etc. 

420. White Light is composed of seven colors. These seven 



IOO PHYSICS. 

colors are red, orange, yellow, green, blue, indigo and violet — 
the colors of the rainbow; 

If a beam of light admitted through a vertical slit be made 
to pass through a prism so placed that its edges are parallel 
with the sides of the slit, and the beam caught upon a screen, 
a band of the seven colors above named will appear on the 
screen. This band of the seven prismatic colors is called the solar 
spectrum, the white light being decomposed into its seven constit- 
uents in its passage through the prism. 

421. Refraction. — When light passes obliquely into a medium 
of different density, the rays are deviated from their original 
direction. 

This tendency of the luminous rays to be refracted or bent 
in passing obliquely from one transparent medium into another 
is called refrangibility. 

The different color rays are not susceptible of refraction in the same degree; 
the red ray is the least refrangible or is less bent than the others, while the 
violet ray is the most refrangible. 

It is this unequal refrangibility that produces the spectrum or band of 
colors (420). 

422. Simple or primary colors. — The seven prismatic colors can 
not be decomposed or made to undergo any change of color, and 
are, therefore, called the simple or primary colors. Recombined 
the primary colors produce white light. 

423. Complementary colors are any two colors which will pro- 
duce white when combined. Red and green rays will produce 
white light and are, therefore, complementary; blue and orange, 
violet and yellowish-green, and indigo and orange-yellow are 
also complementary colors. 

424. Color is produced by the light reflected by the various 
bodies. A body which absorbs all of the colors of the rainbow, 
reflecting none, appears black; one that reflects all the color rays, 
absorbing none, appears white; all other bodies appear to have 
the colors which they, respectively, reflect. A red substance 
seems red because it reflects only red rays of light, absorbing all 
the other rays. 



PHYSICS. 10 1 

425. Fluorescence.- — Some substances have the power of chang- 
ing their refrangibility of rays of light. The result of this is a 
change of color apparent upon the surface of these bodies, a 
bluish, greenish, or even reddish glimmer being diffused by them. 

Fluor-spar, an acid solution of sulphate of quinine, tincture of turmeric, 
the fluid extracts of gelsemium and stramonium seed, and many other organic 
substances exhibit fluorescence. The glucoside aesculin contained in horse- 
chestnut bark has this property in a marked degree, one grain being sufficient 
to impart a distinct fluorescence to over twenty gallons of water. 

426. Rays of light have three properties ; they are: 1, lumi- 
nous; 2, heating; and 3, producing chemical action. 

The luminous intensity is greatest in the yellow, and least in 
the violet rays. 

The intensity of heat is least in the violet and increases to (and 
beyond) the red. The spectrum contains invisible dark rays of 
heat, which are less refrangible than the red rays. 

Light has a marked influence upon chemism. 

427. The chemical action of light is necessary to the healthy growth of 
plants. Many plants do not thrive at all in the shade. For the elaboration of 
their food plants need the light as well as the heat of the sun's rays, and those 
rays of light which favor chemical reaction are of vital importance. 

The bleaching power of light depends upon its chemical effect. 

That light has very great power in this direction is shown by many of 
the familiar changes occurring in medicinal chemicals, as the darkening of 
yellow oxide of mercury, white precipitate, pyrophosphate of iron, etc., on 
exposure to light. Photography is based upon the decomposition of silver 
compounds by light. Hydrogen and chlorine combine very slowly in diffused 
light, but with explosive violence in direct sun-light. 

428. But the chemical effect of the different rays is not equal. It is 
hardly perceptible in the red and yellow rays, but increases gradually toward 
the opposite end of the solar spectrum, becomes decided in the blue, and 
reaches its maximum intensity in and beyond the violet. Thus the chemical 
effect of the rays increases with their refrangibility, and the spectrum contains 
rays beyond the violet which are more refrangible than the violet rays, but 
not visible. 

429. The chemical effect of light renders it necessary to pro- 
tect medicinal substances from its action. 

Containers of colorless flint glass are, therefore, not suitable for holding 
substances affected by light ; blue or violet glass bottles, instead of affording 



102 PHYSICS. 

protection, hasten the decompositions or changes produced by light, as they 
transmit the chemical rays freely, while red, yellow, or amber-colored glass 
affords good protection by excluding the chemical (or " actinic ") rays. 

The damaging effects of direct sun-light upon medicines are more far- 
reaching than is commonly supposed. 



CHAPTER XXIII. 

ELECTRICITY. 



430. Electricity can not be defined since it is not known 
what it is. It manifests itself by peculiar and striking phe- 
nomena of attraction and repulsion and in various other ways. 

Electricity may be converted into all other forms of energy, and all other 
forms of energy can be converted into electricity (66). 

431. Examples of the wonderful effects of electricity are seen 
in the lightning, the telegraph, electric lighting, the compass, 
magnets, electric motors, the telephone, etc. 

432. There are two principal sources of electricity — friction 
and chemism. 

Electricity developed by friction is called frictional electricity, 
or static electricity, It is also sometimes called " Franklinism." 

Electricity developed by chemism is called galvanic electricity, 
or voltaic electricity, or dynamic electricity. 

433. Magnetism is a manifestation of the electric force. 
The power of the lode-stone to attract iron is magnetism. 

Lode-stone is an iron ore called "magnetic oxide of iron," and is a 
natiaal magnet. 

Artificial magnets may be made by means of dynamic electricity. 

434. While electric force developed by different means may exhibit 
differences as to some property, yet these differences are only differences as 
to degree and not as to kind. All the different forms of electricity are iden- 
tical, each having all the properties of any other. 



PHYSICS. 103 

435. It has already been stated (430) that electricity exhibits 
striking phenomena of attraction and repulsion. This is 
because electricity has two opposite states, one called positive 
electricity and the other negative electricity. 

Both kinds of electricity are always simultaneously produced. 

If a lode-stone is rolled about in iron filings the iron will adhere to it, 
especially at the two opposite ends, which are called the poles of the magnet ; 
each pole attracts iron or any other magnetic substance ; but two magnets 
brought end to end will not attract each other regardless of which ends are thus 
brought together, for each end of the first magnet will attract but one end of 
the second magnet and will repel the other end. 

436. An artificial magnet, or a steel needle which has been 
magnetized, poised at the center so that it will swing freely, is a 
compass. One of its ends always points toward the north and is 
called the north pole ; the opposite end is called the south pole. 
The north pole of one magnet attracts the south pole of the 
other, but if the north poles of two magnets are brought together 
repulsion takes place instead of attraction. Thus opposite poles 
attract while like poles repel each other. 

Electricity is, therefor called a polar force. 

437. Induction. — A piece of soft iron, or a piece of steel, 
may be magnetized by being brought near one of the poles of a 
magnet. The soft iron will become a temporary magnet, with its 
two poles, capable of attracting iron ; but it will soon lose its 
magnetic power. A rod of steel, on the other hand, treated in 
the same manner, becomes a permanent magnet. 

This power of any magnet to develop magnetism in a piece 
of iron or steel is called Induction. The magnet thus used to 
make another magnet does not lose any of its force. 

438. Magnetic substances are such as are attracted by a mag- 
net ; among them are iron, steel, nickel and cobalt, and in less 
degree magnetic are manganese, chromium, platinum, plumbago 
and oxygen. 

439. Certain substances exhibit a remarkable property in reference to 
magnetism. If suspended between the poles of a powerful magnet in the 
shape of a horseshoe, they assume a position at right angles to the line join- 
ing the poles, as if they were repelled by both poles. Phosphorus, bismuth, 



104 PHYSICS. 

antimony, zinc, tin, resin, and hydrogen act in this manner. Such substances 
are called diamagnetic. 

440. Effects similar to those produced by a magnet may be produced by 
very simple means. 

A stick of sealing wax rubbed with dry flannel has the property of attract- 
ing to itself small pieces of paper, shreds of cotton and silk, feathers, gold 
leaf, sawdust, and other light bodies. The stick of sealing wax having been 
negatively electrified by the friction produced by the flannel attracts light 
bodies. But the bodies attracted to the sealing wax become in turn charged 
with the same negative electricity and are then no longer attracted but repelled, 
so that they do not fall off the wax but are really throivnoft.. 

A warm glass rod rubbed with a silk handkerchief, or a silk pad, also 
attracts and afterwards repels light bodies; but the glass is Positively elec- 
trified. 

The polarities of the wax and the glass rod are opposite, and hence the 
bodies repelled by the one are attracted by the other. 

Two bodies charged with like electricities repel each other; but two bodies 
of opposite electrical polarities attract each other. 

441. Other phenomena of electricity which may be readily produced are 
these: 

A hard rubber comb attracts the hairs to itself in the act of being used. 

If you put a piece of zinc upon the tongue and a silver coin under it no 
peculiar sensation is perceived if the metals are not in contact; but if you let 
the metals touch each other at the edge while placing your tongue between 
them, a singular, disagreeable, tingling sensation and taste is developed. 

If you place a silver coin between the upper lip and the teeth instead of 
under the tongue, and the piece of zinc above the tongue, and then bring the 
two metals into contact with each other, the peculiar taste will be perceived 
as before, and, besides, there will be, each time, a momentary flash of light 
appearing to pass before the eye. 

Light is emitted when a cat's fur is stroked in the dark. 

All these are electrical phenomena. 

442. Conductors of electricity are substances which readily 
transmit electricity from one body to another. 

Substances that do not transmit electricity are called non- 
conductors, or insulators. 

But these distinctions are only relative, for there are no perfect conduct- 
ors, nor any perfect insulators. 

443. Active chemism, or a chemical reaction (522), is always 
attended by the development of electricity. The electricity 



PHYSICS. 105 

thus developed js dynamical electricity; while identical with stat- 
ical orfrictional electricity, its discharge is continuous while the 
current of statical electricity is only momentary. 

444. Electric currents are commonly produced by chem- 
ical action between metals and corrosive liquids. 

The voltaic current is thus produced when one strip of copper 
and another of zinc are placed in dilute sulphuric acid in a glass 
jar, the'two strips of metal being connected, above the acid, by 
a wire, which serves as the conductor. This apparatus is called 
a voltaic, or galvanic, element or cell. 

445. A number of voltaic cells connected so that the cur- 
rent has the same direction (446) in all, constitute a voltaic bat- 
tery. 

446. Direction of the Currejit. — The positive current of elec- 
tricity within the liquid is from the zinc to the copper (447), and 
above the liquid from the copper to the zinc, thus producing a 
circuit. To connect the plates by means of the metallic wires 
(copper wire is used), is called closing the circuit, and to separate 
them is to break the circuit. 

447. The current starts from the zinc because that is the metal most 
easily acted upon by the acid, and that metal is, therefore, called the generat- 
ing plate, while the copper is the conducting plate. The generating plate is 
also called the positive plate and the conducting plate the negative plate. 

448. Many different kinds of cells and batteries have been 
invented and several are in use, all based upon the fact that 
chemical reactions produce electricity. 

449. Poles. — If the wires be disconnected, or the current 
broken, the positive electricity will tend to accumulate at the 
end of the wire attached to the negative plate (the copper), and 
the negative electricity on the wire attached to the positive 
plate (the zinc). The ends of the wires are called the poles, or 
electrodes, of the circuit. The wire attached to the negative 
plate is the positive pole, and that attached to the positive plate 
is the negative pole. 

450. Chemical effects of the electric current. If a chemical 
compound be placed between the poles or electrodes of a bat- 



106 PHYSICS. 

tery and thus made to form a part of the external voltaic cir- 
cuit, chemical decomposition will take place. This process of 
decomposition is called electrolysis, and any substance capable of 
electrolytic decomposition is called an electrolyte. 

Electrolysis proves a remarkably intimate analogy between 
electricity and chemism which will be referred to again. 

451. Electroplating and electrotyping are performed on the principle of 
electrolysis, the metal being separated from its salt and deposited on the nega- 
tive electrode, which may consist of the article to be plated provided it pos- 
sesses a conducting surface. 



PART II 



CHEMISTRY. 



PART II 



CHEMISTRY 



CHAPTER XXIV.— Introductory. 

MASSES, MOLECULES AND ATOMS. 

452. The three great divisions of the material world are the 
Animal Kingdom, the Vegetable Kingdom, and the Mineral 
Kingdom. 

All natural material objects around us belong to one or 
another of these three kingdoms. The artificial material things, 
which are the result of man's labor, may be made up of matter 
derived from two or all three kingdoms of Nature. 

453. Inorganic or Mineral Substances are those belong- 
ing to or derived from the mineral kingdom. They include 
stones, earth, metals, and all chemical compounds, except the 
compounds of carbon and hydrogen and their derivatives. 

The metallic salts, as the compounds of potassium, sodium, calcium, zinc, 
iron, mercury, lead, etc., and the " mineral acids," as sulphuric, phosphoric, 
nitric, hydrochloric and hydrobromic acids, are thus all inorganic compounds. 

454. Organic Substances are those belonging to or 
derived from the animal and vegetable kingdoms, and the 
numerous derivatives of the hydrocarbons and many other 
carbon compounds. 

All our plant drugs and animal drugs, together with the substances 
extracted from them, as alkaloids, gums, resins, etc., and all our fluid and 
solid extracts are among ihe organic substances. Acetic, oxalic, citric, and 
tartaric acids, tannin, santonin, sulphate of quinine, sugar, starch, alcohol, 
glycerin, ether, chloroform — all are organic substances. 

109 



110 CHEMISTRY. 

455. By far the greater number of bodies in nature are 
made up of various substances in various proportions. They 
consist of unlike masses and unlike molecules mixed together. 
This is true of both organic and inorganic bodies. It is strik- 
ingly evident that all animal bodies consist of many different 
substances, some solid and some liquid, some hard and others 
soft, some of one color and others of another color, etc. Plant 
tissues, as wood, etc., also consist of many different things. 
These are, therefore, heterogeiieous masses, or mixed substances. 

456. But there are also many bodies which appear, even 
upon close examination, to have a perfectly homogeneous mass 
throughout. Water is thus uniform. It appears to be of per- 
fect sameness in every minutest particle of its mass; and, in 
reality, it is but one substance or kind of matter. A large num- 
ber of minerals, ores and metals also appear to be, and really 
consist of but one kind of matter throughout their mass. Other 
bodies, again, which have the appearance of perfect sameness in 
their every least particle, nevertheless consist of more than one 
kind of matter, as is the case with air, solutions and mixtures of 
certain liquids. 

457. If a piece of sugar be put in a tumblerful of water, the sugar dis- 
solves and the sugar and water form a solution, in which they are so inti- 
mately blended that every drop of the liquid is precisely like every other 
drop, and it is impossible to distinguish the particles of water from the 
particles of sugar in that liquid. Yet, we can separate the water from the 
sugar, for the water is vaporizable, while the sugar is fixed; and, hence, the 
water can all be evaporated, leaving as a residue the whole amount of sugar 
which we put into the water. Therefore, the water and sugar must have been 
blended or intermingled with each other without losing their respective 
identities, every particle of either of them remaining wholly distinct from 
every particle of the other, although we could not see this to be the case, the 
particles being too minute to be perceptible, even with the aid of the most 
powerful microscope. 

458. If you mix together, by trituration, in a mortar, one scruple of 
calomel and one scruple of sugar, the result will be a mixture so perfect that 
it looks as if it were but one substance. But if you mix this powder with an 
ounce of water in a dish; pour off the water which washes out the sugar by 
dissolving it; repeat the washing with fresh portions of water until the water 
no longer acquires any sweetish taste, and then let the residue dry, and weigh 



CHEMISTRY. in 

it, you will find that residue to be the one scruple of calomel. The sugar and 
the calomel were neither of them lost or altered by being triturated together, 
but were only mixed, and their separation was easily accomplished by simple 
physical means. 

459. If you mix an ounce of alcohol and an ounce of glycerin, the mix- 
ture looks quite as uniform as water; but if you heat the mixture in a dish 
over a water-bath a sufficient time, all the alcohol will be driven off, and the 
glycerin will all remain in the dish. 

460. Mix 20 grains of each of magnesia, sugar, rosin and charcoal, and 
reduce all to a uniform fine powder. It looks as if it were but one substance. 
Now mix it with enough water to make a thick fluid; transfer this to a paper 
filter in a small glass funnel; rinse the mortar and pestle with a little more 
water so as to get all of the powder added to the rest on the filter. Collect 
the liquid which runs through the filter; evaporate it to dryness and weigh 
the residue. Let the filter and contents dry. Then add to the powder in the 
filter just enough alcohol to moisten both the filter paper and contents, and, 
after a few minutes, add enough alcohol to cover the whole of the black mass 
in the filter, and collect all of the liquid that passes through, and evaporate it 
to dryness and weigh the residue. Allow the filter and contents to become 
nearly dry again, and then treat the remainder of the mixture in the filter 
with a mixture of sixty minims of diluted sulphuric acid and one-half fluid 
ounce of water in the same manner as you before treated the contents of the 
filter with alcohol; collect the liquid that passes through and evaporate it to 
dryness. Then wash the residue on the filter with two fluid ounces of water 
by pouring that water into the filter on the contents and letting it run through. 
Collect this filtrate also and evaporate a portion of it to dryness. 

Now, examine your several residues. You will find, if you have done 
your work well, and used enough of the water in the first, and of the alcohol 
in the second washing, that the first residue is your sugar, and the second 
residue is your rosin. The third residue, however, is neither sugar, rosin, 
magnesia nor charcoal, but a bitter white substance, soluble in water, quite 
unlike magnesia; it is, in fact, Epsom salt, and weighs over seventy grains. 
The last wash water will leave no residue, and if you now put the filter and 
contents in a dish over the water-bath and dry them perfectly, you will find 
that when they are put on the pan of the balance their total weight is about 
twenty grains, in addition to the weight of a paper filter of the same size as 
used in your experiment; that will account for your charcoal, which all remains 
in the filter to the last. If you taste the sugar, burn the rosin, and also sub- 
ject the charcoal to such simple physical tests as you can think of, you will 
conclude that they are these substances and no other. , 

In this experiment it is shown that the original mixture of the four 
powders contained at least the sugar, rosin and charcoal unchanged. Indeed, 



112 CHEMISTRY. 

the magnesia, too, was unchanged in that mixture, but the sulphuric acid 
turned it into Epsom salt, which is water soluble, and it was thus separated 
from the charcoal. This change of the magnesia to Epsom salt was a chemical 
change. 

461. But sometimes it is very difficult to determine by 
physical means whether or not a body is a mixture of different 
substances, or but one single substance. 

462. All kinds of matter consist of one or more kinds of 
ato??is united into molecules. 

463. Atoms, as already stated (20), are the smallest par- 
ticles into which any kind of matter can be sub-divided. Thus 
they are the absolutely indivisible particles of matter, of which 
all molecules and masses are made up. The} r are the smallest 
particles of matter which can take part in chemical reactions (522) 
or combinations. As atoms are indivisible, they are, therefore, 
of course, also undecomposable. 

An atom can pass simply from one molecule to another, or a group of 
atoms liberated from one molecule may be re-arranged into other molecules; 
but it is held that no other atom can continue to exist singly, independently, or 
alone, or in a free state, or uncombined with some other atom or atoms. 

464. Kinds of Atoms. — Only seventy different kinds of 
atoms, or seventy kinds of undecomposable matter, are so far 
known to exist. 

It seems probable that some other kinds of atoms not now known are in 
existence and may yet be discovered. On the other hand, it may be that all 
our so-called elements may be found to be but different conditions of but one 
or two kinds of primary matter. 
465. The seventy different kinds of atoms now recognized as 
existing are enumerated in the following 

TABLE OF ELEMENTS AND THEIR SYMBOLS. 



Aluminum 


Al 


Caesium 


Cs 


Antimony (Antimonium 




Calcium 


Ca 


or Stibium) 


Sb 


Carbon (Carboneum) 


C 


Arsenic (Arsenicum) 


As 


Cerium 


Ce 


Barium 


Ba 


Chlorine (Chlorum) 


CI 


Beryllium (See Glucinum) 


Be 


Chromium 


Cr 


Bismuth (Bismuthum) 


Bi 


Cobalt (Cobaltum) 


Co 


Boron 


B 


Columbium 


Cb 


Bromine (Bromium) 


Br 


Copper (Cuprum) 


Cu 


Cadmium 


Cd 


Didymium 


Di 





CHEMISTRY. 


113 


Erbium 


Er 


Potassium (Kalium) 


K 


Fluorine (Fluorurrn 


F 


Rhodium 


Rh 


Gallium 


Ga 


Rubidium 


Rb 


Germanium 


Ge 


Ruthenium 


Ru 


Glucinum 


Gl 


Samarium 


Sm 


Gold (Aurum) 


Au 


Scandium 


Sc 


Hydrygen (Hydrogenium) 


H 


Selenium 


Se 


Indium 


In 


Silicon (Silicium) 


Si 


Iodine (Iodum) 


I 


Silver (Argentum) 


Ag 


Iridium 


Ir 


Sodium (Natrium) 


Na 


Iron (Ferrum) 


Fe 


Strontium 


Sr 


Lanthanum 


La 


Sulphur 


S 


Lead (Plumbum) 


Pb 


Tantalum 


Ta 


Lithium 


Li 


Tellurium 


Te 


Magnesium 


Mg 


Terbium 


Tb 


Manganese (Manganum) 


Mn 


Thallium 


Tl 


Mercury (Hydrargyrum) 


Hg 


Thorium 


Th 


Molybdenum 


Mo 


Tin (Stannum) 


Sn 


Nickel (Niccolum) 


Ni 


Titanium 


Ti 


Niobium (see Columbium) 


Nb 


Tungsten (Wolframium) 


W 


Nitrogen (Nitrogeniumj 


N 


Uranium 


U 


Osmium 


Os 


Vanadium 


V 


Oxygen (Oxygenium) 


O 


Ytterbium 


Yb 


Palladium 


Pd 


Yttrium 


Yt 


Phosphorus 


P 


Zinc (Zincum) 


Zn 


Platinum 


Pt 


Zirconium 


Zr 



The name Beryllium is now obsolete, the name Glucinum having taken 
its place. The name of Niobium has been changed to Columbium. Finally 
Didymium has been recently split up into two kinds of atoms called Neo- 
didymium and Praseo-didymium. Thus the different kinds of atoms in the 
preceding table are seventy in number. 

466. Endless as is the variety of substances, all material 
bodies in Nature, so far as at present known, are aggregations 
of molecules (470), each made up of one or more of this limited 
number of atoms (465). 

467. Atoms are endowed with chemical energy caused by a 
force called chemism, or chemical force. Chemism is also called 
combining power, chemical attraction, chemical affinity and atomic 
attractio?i. 

Atoms are united with each other by this force into mole- 
cules, and can not be separated from these molecules unless 
under such conditions that they may immediately form new 
molecules. 

468. All atoms of the same kind have the same size and the 
same weight. But atoms of different kinds have different 



114 CHEMISTRY. 

weights. The absolute weight of any atom is unknown; but its 
relative weight, being constant, can be determined in several 
different ways with great accuracy. 

469. Whenever any two or more atoms unite with each 
other by virtue of the chemical attraction between them, and 
their chemical affinities are thus satisfied or neutralized, a mole- 
cule (470) is the result. 

When the atoms thus unite, their chemical affinities are spent 
or satisfied. Molecules, therefore, have no chemical energy or 
affinity, and can consequently continue in independent exist- 
ence. 

470. Molecules, as already stated elsewhere (16), are the 
smallest particles of any kind of matter that are capable of 
continued existence as such. They are the smallest particles 
into which any kind of matter can be divided without losing 
its identity, or without being thereby converted into some other 
kind or kinds of matter; for when molecules are divided into 
their constituent atoms they cease to exist, and the atoms form 
new molecules. 

471. Masses are made up of molecules. Molecules are 
either elemental or compound. 

Elemental molecules consist of atoms of but one kind. 
Compound molecules are composed of more than one kind 
of atoms. 

472. Elements are substances consisting of elemental 
molecules (471). 

In an element, therefore, the mass, the molecule and the 
atom each consist of one and the same kind of matter. 

The elements, therefore, can not be decomposed into other 
kinds of matter. • 

There are accordingly as many elements as there are differ- 
ent kinds of atoms. Thus, seventy elements are at present rec- 
ognized (465). 

Upon examination of the table of elements (465) you will 
find in it all of the known metals. In fact, about four-fifths of 
the elements are metals. 



CHEMISTRY. 115 

Of the whole seventy only five elements are gases at the com- 
mon temperatures, two are liquids, and all the others solids. 

473. Chemical compounds are substances consisting of but 
one kind of compound molecules (471). 

Any substance containing more than one kind of molecules is not a 
definite chemical compound but is a mixed substance (482). 

We have learnt that there are but seventy different kinds of 
matter called elements; all other distinct kinds of matter are chemi- 
cal compounds, or compound matter. 

474. Chemically homogeneous bodies are such as consist 
of but one kind of molecules, whether elemental or compound. 
All elements and all chemical compounds are therefore chemi- 
cally homogeneous. 

475. As all masses of matter are made up of molecules, and 
the molecules are the smallest particles into which matter can 
be divided without being changed into some other kind or kinds 
of matter (470), the mass is divisible into molecules without 
change of kind, but the molecule can not be split up into its 
constituent atoms without ceasing to be the same kind of matter 
(15 and 17). 

476. Number of kinds of matter. — There are as many dis- 
tinct kinds of matter as there are different kinds of molecules 
and vice versa. 

They are countless. 

477. Each molecule of any one chemical compound invaria- 
bly contains the same total number of atoms, the same kinds of 
atoms, and the same number of each kind of atoms, and all its 
atoms are always in precisely the same positions relative to each 
other. 

478. No two bodies or masses can both consist of one and 
the same kind of molecules without being the same kind of 
matter. 

479. All molecules of the same kind have also the same size 
and the same weight; and all molecules whatsoever, whether of 
the same kind or not, have the same volume when in a state of 
vapor. 



Il6 CHEMISTRY. 

480. Each chemical compound, because it has precisely the 
same chemical composition and structure (477) under all cir- 
cumstances, has also precisely the same chemical properties; 
and, moreover, each distinct kind of matter has uniformly the 
same physical properties under the same conditions. 

481. Any two or more bodies having the same chemical and 
physical properties must consist of the same kind of matter. 

482. Mixed Substances, or heterogeneous masses, are bodies 
consisting of more than one kind of molecules. A mixture, or 
mixed substance, is made up of as many different substances 
as there are different kinds of molecules in it. 

483. Recapitulation. — Every body or mass of matter of 
whatever kind is an aggregation of molecules. These mole- 
cules are held together by cohesion if of the same kind, but by 
adhesion if of different kinds. 

Each molecule is the smallest individual particle of any 
kind of matter having the properties of the whole mass, and, 
therefore, the smallest particle of any kind of matter that is 
capable of subsisting. 

In any one distinct kind of matter every molecule is like 
every other molecule and like the whole mass. 

There are as many different kinds of matter as there are 
different kinds of molecules, and no more. 

Every molecule of any one particular kind has exactly the 
same weight and the same volume as every other molecule of 
the same kind ; and all molecules of the same kind, moreover, 
contain each the same number of atoms, the same kinds of 
atoms, the same number of each kind of atoms, and the same 
internal atomic structure or grouping of the atoms. 

All molecules of whatever kind, when in a state of vapor, 
have the same volume. 

As the kind of matter is determined by the composition and 
structure of its molecule, any change in the composition or 
structure of its molecule involves the change of that kind of 
matter into a new or different kind or kinds of matter. 

All molecules are made up of atoms united by chemism. 



CHEMISTRY. II- 

There are seventy different kinds of atoms. 

Atoms are absolutely indivisible particles of matter. 

All atoms of the same kind have the same weight and the 
same volume.. 

The different kinds of molecules or different kinds of matter 
are countless; yet they all consist of one or more of the seventy 
different kinds of atoms, so far as at present known. 

When atoms of but one kind form molecules, the resulting 
molecules are simple kinds of matter, or elements; there are, con- 
sequently, as many different elements as there are different 
kinds of atoms, and no more. 

But when unlike atoms, or atoms of different kinds, unite, 
the molecules thus formed are compound matter. 

A chemically homogeneous mass is a mass composed of but 
one kind of molecules. Such a body is called a definite chem- 
ical substance. If all the molecules of such a mass consist 
of but one kind of atoms, the mass is that of an element; if they 
consist of more than one kind of atoms, the mass is that of a 
definite chemical compound. 

But the greatest number of material objects or bodies in 
nature have masses composed of different kinds of molecules, 
and are not chemical compounds but only mixtures, each 
ingredient of which is distinct from every other ingredient in it. 



484. Physical Properties. — The physical properties of 
matter are those which belong to their masses and molecules. 
They include among others the form, state of aggregation, 
consistence, specific weight, vapor density, specific volume, 
color, odor, taste, solubility, melting point, congealing point, 
boiling point, etc. 

485. Physics is that part of physical science (486) which 
concerns the states and changes of matter without (outside of) 
the molecules, and thus the physical properties (484)- But 



Tl8 CHEMISTRY. 

physical changes can not involve the essential physical proper- 
ties of matter because they do not affect its identity or kind. 

Physics is the scientific study and knowledge of molar and molecu- 
lar matter. 

486. Physical Science is the systematic pursuit and classi- 
fication of all knowledge of matter and of the forces by which 
matter is affected. 

It takes cognizance of the bodies of matter, the conditions, 
motions and changes to which these bodies are subject, and the 
laws governing the phenomena of physics and chemistry. 

487. The Chemical Properties of matter are those proper- 
ties which depend upon its atoms alone. They include the rel- 
ative weights, valence (607), chemical energy (514) and electro- 
chemical polarity (564) of the atoms; and the relative weights, 
structure, and analytical and synthetical reactions (522) of the 
molecules. 

488. Chemistry is that part of physical science which 
treats of the structure ancl changes of matter within the mole- 
cule. 

It is the science of the constitution and relative stability of 
molecules. 

// is the scientific study and knowledge of atomic matter. 



CHAPTER XXV. 

CHEMICAL PHENOMENA. 



489. Chemical Phenomena. — We have learnt (27) that 
matter is indestructible, or that it can not be annihilated. By the 
agency of chemism one kind of matter can be transformed into 
some other kind or kinds of matter; but it can not be changed 
as to its amount. The amount of matter in the universe can 



CHEMISTRY. 



II 9 



neither be added to nor diminished, for it is uncreatable as well 
as indestructible. 

490. Any substance may undergo change, and this change 
may be so great as to involve loss of identity; but in every such 
case the matter of which that substance was composed has not 
been destroyed but has simply been transformed into some other 
substance or substances. 

When alcohol burns it disappears from sight, and as alcohol it no longer 
exists. But the matter of which the alcohol was constituted has not been 
destroyed. The elements of which alcohol is composed are carbon, hydrogen 
and oxygen ; these three elements are capable of forming numerous compounds 
with each other and alcohol is one of these compounds. When alcohol is 
ignited it is decomposed by the combustion, and its carbon, hydrogen and 
oxygen, together with a certain amount of oxygen from the air, pass into 
other combinations — carbon dioxide and water — which are invisible in the 
gaseous state assumed by them when formed by the combustion of the alco- 
hol in the air. 

491. Whenever any substance is, as we say in common par- 
lance, totally destroyed by fire, that substance may so completely 
lose its identity or its properties that it can no longer be recog- 
nized, and indeed is no longer the same substance; but instead 
of being lost or annihilated it has been transformed into other 
kinds of matter, and if the apparent destruction of the substance 
be accomplished under such conditions that the new products 
formed out of the substance so destroyed can be collected and 
weighed it is found that every particle of the original substance 
can be accounted for as entering into these new products. 

492. Any two or more chemically homogeneous bodies 
(474) exhibiting, respectively, different properties can not sev- 
erally consist of the same kind of molecules. 

493. Whenever any body acquires permanently different 
properties by being subjected to the action of heat, light, air, 
moisture, or an electric current, or by contact with another 
body, or from any cause whatsoever, it has ceased to be the same 
kind of matter as before. It has been converted into some other 
kind of matter, or undergone a chemical change ; or chemical reac- 
tion, or chemical decomposition, and these changes, reactions, or 
decompositions are chemical phenomena. 



120 CHEMISTRY. 

494. No two or more different kinds of matter have pre- 
cisely the same physical properties in all respects. 

Whenever any kind of matter is changed as to its kind it is 
also changed as to its physical properties. 

Mere mixtures or heterogeneous masses may, however, be 
changed as to their properties without loss of identity of the 
several ingredients ; any admixture changes the character of 
the whole. 

495. Among the physical properties of matter are form, 
color, odor, and taste. Any one kind of matter always has 
the same physical properties under the same (or unchanged) 
conditions. 

Lead iodide is always yellow. A yellow color does not prove that the 
substance having that color is lead iodide ; but the absence of the yellow color 
does prove that the substance is not lead iodide. 

Ammonia has a peculiar, strong odor. Any substance which does not 
possess that odor can not be ammonia. 

An acid liquid can not be sugar, for sugar is a solid and has a sweet 
taste. 

Salicin can not be mistaken for potassium iodide, for salicin consists of 
bitter, silky, slender crystals, while potassium iodide has a pungent, saline 
taste and crystallizes in cubes. 

A water soluble solid can not be calomel, nor can a crystalline precipitate 
be castor oil. 

496. A change produced in the physical properties of 
bodies accompanies any chemical change which they may be 
made to undergo. 

Indeed striking changes in the color, odor, or other physical 
properties of a body generally denote that it has been con- 
verted, in whole or in part, into some other kind of matter. 

497. Many chemical changes proceed quietly and unac- 
companied by any marked physical signs, but many other chem- 
ical changes are attended with striking physical phenomena, 
such as fire, explosion, etc. 

Fire is always the result of chemical reaction. 

Explosions of gun powder, dynamite, gun cotton and gas, are caused by 
chemical reactions. 

Other less noisy and less dangerous evidences of chemical change are 
exhibited in the following experiments. 



CHEMISTRY. 12 1 

498. Put two or three little crystals of chromic acid on a piece of paper; 
put about fifteen drops of alcohol in a graduate or bottle, then pour that alco- 
hol over the crystals, and observe the commotion that instantly follows. The 
heat liberated by the reaction ignites the alcohol; hence, it is safer not to add 
the alcohol out of the shop bottle, but to put the small amount required in 
another vessel before adding it to the chromic acid. 

499. Put a little diluted sulphuric acid in a graduate and add to it a little 
potassium carbonate; a lively effervescence takes place and the mixture 
becomes warm. 

500. Place about half a teaspoonful of each of potassium carbonate and 
ammonium chloride in a mortar. Observe before they are mixed that neither 
of them has any odor. Then rub them together and note that the odor of am- 
monia is developed. 

501. Mix four grains of corrosive sublimate in a mortar with five grains 
of potassium iodide; the materials are both white, but the mixture will be 
scarlet red. 

502. Touch a little diluted sulphuric acid with the end of your tongue 
and observe how acid it tastes; taste also a little magnesia, and notice that it 
has only a faint, earthy taste. Then put two fluid-drachms of the diluted sul- 
phuric acid in a graduate and add one drachm of magnesia; stir well, and 
when the liquid no longer dissolves any more of the white powder taste the 
liquid. You will find that it is neither acid, nor of a faint, earthy taste; it is, 
instead, of a cooling, saline, bitter taste. 

503. Dissolve a grain of blue vitriol, or copper sulphate, in two ounces of 
water; observe that the color is very pale bluish; add a few drops of ammonia 
water and see how the color changes to a beautiful deep blue, which does not 
belong to either water, copper sulphate, or ammonia, but to a new substance 
formed in the liquid. 

504. Dissolve one-half grain of sodium salicylate in a half-pint of water; 
add a few drops of tincture of chloride of iron and observe the reddish or pur- 
plish color produced in the mixture; now add about a fluid-ounce diluted 
hydrochloric acid and the color disappears again. 

505. Dissolve thirty grains of pure sulphate of iron (or of clear, green 
crystals of copperas) in half an ounce of water, and dissolve fifteen grains of 
oxalic acid in another half ounce of water; mix the two solutions and observe 
that a yellowish color first makes its appearance and afterwards a yellow pow- 
der is found in the liquid. 

506. Mix one fluid-drachm of tincture of chloride of iron with two fluid- 
drachms of ammonia water and observe that a copious brown-red precipitate 
is formed. 

507. Mix one fluid-drachm of tincture of chloride of iron with two fluid- 
drachms of simple syrup, and then add two fluid-drachms of ammonia water; 



122 CHEMISTRY. 

observe that no precipitate is formed, but a deep brown red color is produced. 
Compare this experiment with that described in the preceding paragraph. 

508. Put a fluid-drachm of syrup of iodide of iron in a graduate and add 
a little solution of potassa; observe the deep green color brought out. 

509. Put one fluid-drachm of tincture of iodine in a one-ounce bottle; add 
about fifteen minims stronger water of ammonia and one drop of carbolic 
acid; shake; observe that the dark iodine color soon disappears, leaving a 
colorless liquid. 

510. The experiments described in paragraphs 498 to 509, inclusive, are 
all examples of chemical reactions accompanied by evident physical signs, 
such as fulmination, effervescence, the development of odor, changes of 
color, change of taste, the discharge of color and the formation of insoluble 
substances in liquids. 

The results of these experiments are sufficiently striking to excite inter- 
est in the causes and effects. And yet how feeble they are beside the won- 
derfully active chemical reaction which we call fire, or the explosion of the 
charge in a gun! 

511. There are numerous examples of slow chemical changes or reac- 
tions all around us which we may witness if we are observing. 

A bright iron nag] exposed to air and moisture will rapidly become rusty; 
the rust is an iron compound formed by chemical reaction, and to recover 
the iron again from that rust requires a chemical process. 

Bright copper or brass turns green when acted upon by air and grease, 
or by vinegar; the green compound is a product of chemical action. 

When limestone is heated in a kiln, it is decomposed and quick lime 
remains; if the quick lime is mixed with water it becomes slaked, heat is gen- 
erated by the chemical action, and the white liquid which results does not 
contain quick lime by calcium hydrate. Both changes are chemical. 

When copperas is exposed to the air it becomes brown on the surface ; the 
brown substance is not copperas but another compound formed by chemical 
action. 

Nitrate of silver and yellow oxide of mercury darken on exposure to light 
as a result of chemical decomposition. 

Fermentation, by which malt, syrup and sugar yield alcohol, and by 
which weak alcoholic liquids, like cider and weak wines, turn into vinegar, 
is a chemical process. The change by which the rich green of the foliage of 
our forests is changed to the beautifully varied hues of autumn leaves, is also 
the result of chemical reactions. 

The decay of wood and other organic substances, the putrefaction of 
animal matter, the digestion of food — all these are chemical processes, involv- 
ing chemical changes; produced by chemism, and resulting in the decomposi- 
tion of the old molecules and the formation of new ones in their places. 






CHEMISTRY. I 23 

512. Relative Stability of Molecules.— Some substances 
resist chemical influences and changes to a remarkable degree. 
The molecules of platinum, gold, quartz, clay, carbon, and many 
other substances remain unaltered under ordinary conditions. 
On the other hand, there are also numerous substances which 
are easily affected by air, moisture, changes of temperature, the 
influence of light, or by contact with other substances. 

513. Chemical Changes or Reactions or phenomena are 
those changes in matter which extend not only to its physical 
properties, but which involve the very identity of its kind. 

So long as the molecule is unchanged, the matter of which it 
consists remains of the same kind, but when the molecule is 
divided or decomposed, or its interior structure altered, that 
change is a chemical change or reaction, because it changes 
both the physical properties and the kind of the matter. 



CHAPTER XXVI. 

CHEMISM. ITS INTENSITY, QUALITY, AND QUANTITY. 

514. Chemism is the force which manifests itself by atomic 
attraction and repulsion, and by which molecules are formed, 
altered or decomposed. 

It is the force by which matter is altered as to its kind. The 
transformation of any kind of matter into any other kind or 
kinds of matter is effected by chemism, and never directly by 
any other cause (515). 

515. Matter may be altered as to its kind, or its alteration 
may be prevented, apparently by other agencies than chemism, 
but only in an indirect way. 

Heat, light and electricity cause chemical changes to take place; but only 
by aiding chemism, or by producing conditions favorable to the action of 
chemism. 



124 CHEMISTRY. 

Chcmism may be aided or opposed by other forces, and may be converted 
into other forms of energy, or other forms of energy may be converted into 
chemism. But that energy which changes matter as to its kind is always and 
alone chemism. 

516. All atoms are endowed with or subject to chemism. It 
is because of this irresistible force that atoms can not subsist 
singly or uncombined, but are compelled to seek new partners 
as soon as they are liberated from their previous partnership in 
some other molecule, and can thus only pass from one molecule 
to another. 

517. In thus causing and directing the separation, union, or 
rearrangement of the atoms, the chemism of these atoms is 
neutralized, or saturated, or rendered latent. All molecules are, 
therefore, neutral. 

Chemism operates only between atoms; never between mole- 
cules. 

51S. But changes of matter from one kind to another kind 
would be impossible were it not for the separation of atoms 
from each other and their re-arrangement into new molecules. 
It therefore follows that atoms must be made free before they 
can be again tied to or combined with other atoms. At the 
moment of their transfer from one molecule to another they are 
free and endowed with active, unsatisfied combining power or 
chemism. 

519. Radicals. Atoms and groups of atoms whose chemism 
is wholly or partly unsatisfied are called radicals. 

A simple or elemental radical is a single atom in a free state, or 
with all its chemical combining power in full play. All atoms 
in a free state are simple radicals. 

A coj?ipoufid radical is a group of two or more atoms of differ- 
ent kinds, tied together by a part of their chemism, but having 
another part of their chemism still unsatisfied. The atoms in 
such a group act together as one radical, or as if the whole 
group were but one atom. 

Radicals, then, are atoms or groups of atoms liberated from 
molecules, and impelled by chemism to unite with other radicals 
to form new molecules. 



CHEMISTRY. 1 25 

520. Radicals differ as to the intenity, quality and quantity 
of their chemism. 

By inte?isity of chemical energy is meant the relative power of 
the affinity of one radical as compared with that of another (521). 

The quality of the chemism of any radical is indicated by the 
character and conduct of the compounds it forms, and depends 
upon its electro-chemical polarity (564). 

The relative quantity of the chemism of a radical is expressed 
by the term valence (607). 

521. The relative energy or intensity of chemism is in many 
instances very marked. Radicals unite according to their mutual 
attractions or affinities. The attraction between some radicals is 
relatively stronger or weaker than the attraction between other 
radicals. 

Thus the chemical affinity between potassium atoms is weaker than the 
affinity of potassium atoms for the atoms of oxygen, and phosphorus atoms 
have a greater affinity for hydrogen atoms than they have for nitrogen atoms. 

Hydrogen conducts itself as a neutral or chemically indifferent substance 
under ordinary conditions. 

Chlorine, however, attacks other substances with great energy. 

Sulphuric acid is far more energetic in its chemical action than boric acid; 
the sulphuric acid is extremely corrosive and destructive, while boric acid is a 
harmless, inactive substance. 

522. Chemical Reactions. — Any change which takes place 
within a molecule is a chemical reaction. 

Molecules differ according to the kind, number and relative 
position of their atoms. Any change in either of these respects 
is a chemical reaction. The removal of one or more atoms; the 
addition of one or more atoms; the change of one or more of the 
atoms by substituting others of a different kind; or any inter- 
atomic re-arrangement within the molecule by which the rela- 
tive positions of the atoms is altered — either of these changes 
is a chemical reaction. 

523. The Factors of the Reaction are the molecules 
decomposed in any chemical reaction. 

The Products of the Reaction are the new molecules 
formed by it. 



126 CHEMISTRY. 

Thus when iodine and mercury are triturated together in a mortar to 
make iodide of mercury, the iodine and the mercury are the factors and the 
iodide of mercury the product of the reaction which takes place. 

When a solution of acetate of lead in water is mixed with a water solu- 
tion of sulphate of zinc, a white insoluble powder precipitates in the liquid, 
which is sulphate of lead, while water-soluble acetate of zinc remains in solu- 
tion. In this case the acetate of lead and the sulphate of zinc are the factors 
of the reaction, and the sulphate of lead and acetate of zinc are its products. 

524. Reagents. — The factors of a reaction are also called 
reagents. But the term reagent is more especially applied to 
substances employed for the purpose of identifying compounds, 
radicals or elements, by means of reactions accompanied by 
striking results and produced by the reagents added for that 
purpose. Reagents are, therefore, used in analytical processes 

(S-'5). 

525. Chemical reactions are synthetical when their object 
is to obtain certain products; they are analytical when their 
object is to identify substances, or detect their presence, or to 
determine their composition. 

526. Synthesis is the formation of compounds by bringing 
together the radicals necessary to their production under such 
conditions as are favorable to the synthetical reaction desired. 

It is the opposite of analysis. 

Direct synthesis is the formation of but one kind of mole- 
cules from two or more kinds, as when iodide of mercury is pre- 
pared from the elemental molecules of iodine and mercury, or 
when hydrochloric acid and ammonia unite to form ammonium 
chloride. 

Indirect synthesis is illustrated by substitution (842) and by 
double decomposition (529), as in the formation of acetate of 
zinc from acetate of lead as described in par. 523. More than 
one kind of molecules are produced by indirect synthesis. 

527. Analysis. — The decomposition of chemical compounds 
for the purpose of determining their composition is called chemi- 
cal analysis. 

The analysis is qualitative when the object is simply to iden- 
tify the radicals or elements of which a substance is composed 



CHEMISTRY. 127 

without attempting at the same time to ascertain the quantities 
of the component elements or radicals. 

Quantitative chemical analysis has for its object the determi- 
nation of the exact quantities of the elements or radicals of 
which molecules are composed, or the exact quantities of each 
of several kinds of molecules contained in any mixture, solution, 
ore, or other mixed substance. 

528. Chemical Decomposition is the separation of the 
constituent radicals or atoms of a molecule. 

When mercuric oxide is heated above 360 C. (63o° F.) it decomposes into 
mercury and oxygen, its constituent elements. When calcium carbonate is 
heated to redness it decomposes, or splits up, into two new compound mole- 
cules, one of which is calcium oxide and the other carbon dioxide. 

Chemical decomposition may result from the reaction of two or more 
substances upon each other, or a re-arrangement of the atoms within a mole- 
cule may be indirect^ induced bv external causes as by the influence of heat, 
light, or electricity. 

529. Double Decomposition results when two compound 
molecules are brought together which mutually decompose each 
other, the reaction giving rise to two or more new compounds. 

CONDITIONS FAVORABLE TO CHEMICAL REACTION. 

530. Actual contact between the particles of matter is 
necessary to chemical action. 

531. Sometimes dry substances may be made to unite chem- 
ically by simply triturating them together, as when iodine and 
mercury, or sulphur and mercury, are combined, forming iodide 
or sulphide of mercury. But this is rarely sufficient. 

532. When the factors of the reaction are both gaseous, the 
chances are usually more favorable to a complete reaction than 
when they are solid. But oxygen and hydrogen can be mixed 
and the mixture kept for a long time without any chemical 
reaction taking place; and a mixture of chlorine and hydrogen 
can also be kept without change, although the chemical attrac- 
tion between these gases is very strong. An electric spark, or 
the application of a lighted match, will quickly cause the gases 
to unite with violent explosion. The chlorine and hydrogen 



128 CHEMISTRY. 

may react with explosion even by the influence of direct sun- 
light, but not if the mixture be kept in a shaded place. 

533. The most favorable condition in which the factors of 
the reaction can be as to the state of aggregation is the liquid 
condition. At least one of them should, therefore, be liquid if 
possible, and it is still better to have both factors of the reaction 
in that state. 

534. Solids can be rendered liquid either by fusion or by 
solution, some by one method, some by the other, and still 
others by either method. But, for the purpose of facilitating 
chemical reaction, solids are liquefied by fusion only in cases 
where that is the only practicable means (by reason of the 
insolubility of the solids or for other reasons). 

535. Whenever it is possible to bring the factors of the 
reaction together in a state of solution, that is the method pur- 
sued, because in that condition they can be more intimately 
mixed, and react more freely, uniformly and completely. 

536. Heat opposes and often overcomes chemical attraction.. 
It is, therefore, destructive to most kinds of matter. Compar- 
atively few kinds of matter can resist the action of strong fire, 
and numerous substances are decomposed at temperatures not 
exceeding those readily produced by very simple means. But 
even when the heat is insufficient to break up a molecule, it, 
nevertheless, weakens the force with which the atoms are held 
together, just as heat weakens the cohesion of a mass by increas- 
ing the distances between the molecules. 

537. Thus heat causes chemical reactions in such a way 
that it seems to aid chemical attraction, although the opposite 
is true. Heat disrupts existing molecules by causing their 
atoms to separate from each other. But when the molecules 
have been decomposed by heat, the atoms of which they were 
constructed at once rearrange themselves into new molecules 
capable of resisting the high temperature. Heat indirectly 
facilitates certain chemical reactions by giving free play to the 
selective affinities of the atoms whose bonds (615) have been 
severed by its repellant force. 



CHEMISTRY. 129 

538. Action of heat upon salts. — Salts containing water 
lose that water when heated. Water of crystallization is usually- 
expelled already at or even below ioo° C. ; in some cases the 
salts thus heated dissolve in their water of crystallization before 
they lose it. Thus a crystal of sodium phosphate is liquefied by 
heat forming a solution in its water of crystallization. Solu- 
tion of this kind is called aqueous fusion. 

Many anhydrous salts undergo fusion at high temperatures; 
to distinguish this from " aqueous fusion " it is called igneous 
fusion or dry fusion. 

Heat causes the decomposition of many salts, especially of 
those of volatile or unstable acids or bases, except in cases 
where a strongly positive radical is united to a strongly nega- 
tive one. . 

Thus the carbonates are generally readily decomposed by heat, except 
the carbonates of the alkali metals. Chlorates and nitrates are easily decom- 
posed by heat, but phosphates and borates resist it: sulphates of the heavy 
metals are decomposed, but the sulphates of potassium, sodium, barium and 
calcium are not. 

539. Chemism generates heat. — Heat is always liberated 
by chemical action. More or less heat must frequently be 
applied to induce chemical action; but the heat afterwards gen- 
erated by the reaction itself is often sufficient to maintain the 
energy of chemism. 

This fact is well illustrated in our experience with the making of fires; the 
wood or coal must be heated up to a certain point before active combustion 
goes on, after which the fire continues as long as the supply of fuel and air 
is sufficient. 

540. When heat weakens the atomic attraction within a 
molecule without breaking it up entirely, the contact of that 
molecule with another molecule of a different kind may prove 
to result in a reaction even if such action would not take place 
without the aid of the heat, both means being necessary to 
bring it about. 

541. Electricity decomposes many chemical compounds, 
and, therefore, also indirectly causes the formation of other 
compounds to take the place of those decomposed by it, just 
as in the case of the decomposition of molecules by heat. 



130 CHEMISTRY. 

542. Status nascendi. — Chemical reactions take place far 
more readily when the reacting elements or radicals come into 
contact with each other at the instant they are liberated from 
other compounds. 

Sulphur and hydrogen do not combine directly; but when both are simul- 
taneously displaced from their compounds — sulphur from iron sulphide and 
hydrogen from sulphuric acid — they readily unite forming hydrogen sulphide- 

543. Molecular hydrogen has no chemical energy ; but 
atomic hydrogen is energetic enough to decompose nitric acid. 

If hydrogen be generated in one vessel, and passed through a tube into 
another vessel containing nitric acid, the gas (molecular hydrogen) will have 
no effect whatever upon the nitric acid no matter how long continued the 
current of hydrogen may be. But if hydrogen be slowly generated in the 
nitric acid itself by dissolving metallic iron in the cold dilute acid, no 
evolution of gas takes place although hydrogen is set free from the nitric 
acid, iron taking its place in the molecule of the acid, because the nascent 
h:drogen — the atomic hydrogen at the moment of its liberation and before its 
atoms unite to form molecules — decomposes another portion of the nitric acid 
forming ammonia and water (HN0 3 +4H 3 ==NH S + 3H 2 0) so that the result- 
ing solution will finally contain not only iron nitrate but also ammonium 
nitrate. 

544. Chemical reactions are also affected by physical forces, 
both as to their energy and their direction. 

Cohesion and adhesion exert an important influence upon the 
course of chemical reactions, in both dry processes and wet pro- 
cesses (545 to 547). 

545. Dry processes or methods are those in which the fac- 
tors of the reaction are dry substances, either in powder, pieces, 
or in a state of fusion. 

Thus when preparations are made by trituration, fusion, exsiccation, cal- 
cination, sublimation, etc., they are said to be made by the " dry way." 

546. Wet processes are those in which one or both factors 
of the reaction are in a state of solution. 

All precipitates are prepared by the "wet way," and also many of the 
water-soluble salts. 

547. In wet processes involving double decomposition (529) 
— that is, when reactions are induced between substances in a 
state of solution — the direction, velocity, and completeness of 



CHEMISTRY. 



131 



the reaction depend greatly upon the relative solubilities of the 
products. 

In dry processes where heat is applied, the reaction which 
takes place, if any, and, indeed, the very question whether any 
reaction will ensue or not, depends in many cases upon the state 
of aggregation or cohesion of the possible products — that is, 
upon whether or not the products are fixed or volatile substances. 

548. The predisposing affinity of a third molecule is 
sometimes of great importance as a means of inducing chemical 
reaction between two other molecules. In other words A and B 
may not react with each other in the absence of adventitious 
influences, but may do so in the presence of another body, C, 
which stands ready to react with one of the products of the 
reaction between A and B. 

The general tendency of all matter is to form as neutral and 
permanent molecules as possible under the conditions under 
which it is placed. A negative radical, therefore, determines or 
predisposes the formation of a positive one with which it may 
be united, and vice versa, in order that the final result may be a 
more firmly united and stable molecule. Strong acids and 
strong alkalies exert a destructive influence upon many neutral 
substances for this reason. 

In chemical reactions which are accompanied by a change of the valence 
of elemental radicals, the cause of such a change can hardly be looked upon 
as any other than this predisposing affinity which compels the formation of 
the strongest possible compound radicals, that can be formed out of the atoms 
taking part in the reaction. 



CHAPTER XXVII. 

THE LAW OF OPPOSITES IN CHEMISTRY. 

149. The opposite properties of acids and alkalies are 
among the most striking facts of chemistry. The destructive 
properties of both have been known since ancient times, and are 
so pronounced and so important as to be familiar to most per- 



132 CHEMISTRY. 

sons of the present time. The sour, corrosive properties of the 
stronger acids are opposite to the caustic properties of the alka- 
lies, and acids and alkalies neutralize each other, so that the 
properties of both are nullified. 

These facts were observed long before chemistry assumed 
the dignity of a science. 

550. Acetic acid in the form of vinegar is mentioned in the 
books of Moses, and was used in medicine by Hippocrates and 
Dioscorides. 

Nitric acid was made by Geber in the seventh century, and 
"muriatic acid " was also known at a very early period. The 
Arabs knew how to make "aqua regia," which is a mixture of 
nitric and muriatic acids, and they were acquainted with the 
fact that gold could be dissolved in that mixture. " Oil of vit- 
riol," which is an old name for sulphuric acid made from "green 
vitriol," was made as early as the 15th century. 

551. The lye of wood ashes was well known, and the solid 
"fixed alkali," which was obtained from it (the impure " pot- 
ash"). Lime, too, has attracted attention, and its effect in 
increasing the alkaline character of potash and soda. Sodium 
carbonate is referred to in the Old Testament, and the ancients 
applied the name nitrum to it. Ammonia was recognized as an 
alkali, being known as a constituent of urine after standing 
(and we still hear the expression "chamber-lye"). It was also 
made from ammonium chloride, known at least as early as in 
the 7th century. Later, potash was called "alkali vegetabile," 
soda (sodium carbonate) was named "alkali minerale," and 
ammonia, "alkali volatile." 

552. The fact that acids and alkalies neutralized each other's 
corrosive properties was too striking to remain unobserved. 
Acid and lye saturated each other and neutral compounds 
resulted which had properties entirely different from those of 
either of the materials which were mixed. 

When vinegar was poured upon chalk, the chalk was dis- 
solved and effervescence took place. The gas which caused 
this effervescence as it passed off received later the name of 
"acid of air." 



CHEMISTRY. 133 

553. But it was further known that some acids and some 
alkalies are stronger than other acids and alkalies, respectively. 
It was recognized that sulphuric acid ("oil of vitriol ") would 
decompose nitre, whereby nitric acid was obtained, and that it 
would also decompose common salt, whereby muriatic acid was 
gotten. 

It is true the early chemists did not know the acids, bases 
and salts by their present names, and did not know their chem- 
ical composition and formulas; but they knew their striking dif- 
ferences. 

554. The metals potassium and sodium were separated from 
the fixed alkalies by means of electricity by Sir Humphrey 
Davy; and the discovery of oxygen and chlorine, and of the 
true nature of combustion, led to a classification of the elements 
into the metallic and non-metallic groups, which further empha- 
sized the opposite character of their most important compounds. 

555. Acids (883) and bases (874) were carefully studied. It 
was discovered that both classes of compounds, as a rule, con- 
tained oxygen ; but that the metallic oxides (846) were basic 
(848), whereas the oxides of the non-metallic elements (847), con- 
taining a comparatively larger proportion of oxygen, produced 
acids. Consequently the salts were assumed to be composed of 
metallic oxides with the anhydrides of the non-metallic elements, 
and potassium sulphate, which is now written K 2 S0 4 , was then 
written KO. S0 3 . What was then called an acid is now called 
an anhydride. But the main fact is — they were of opposite 
chemical properties and neutralized one another. 

556. Simultaneously with the introduction of the balance 
and the discovery of oxygen came the researches and discoveries 
of Volta and Galvani in the field of electricity. 

The intimate relations between chemism and electricity were 
recognized. Not only was the galvanic current produced and 
maintained by the aid of chemical reactions, but the current 
seemed to have an almost unlimited power to resolve chemical 
compounds into two constituents; one of which was invariably 



134 CHEMISTRY. 

attracted to the positive electrode and the other to the negative 
electrode. Salts were thus-decomposed with the result that the 
acid collected at the positive pole, and the base at the negative 
pole. Other compounds have been decomposed in the same 
way and with similar results. 

557. We have before learnt (443) that electricity is devel- 
oped by chemical action, and that the electricity thus developed 
is cal led galvanic or voltaic electricity, being so named after Gal- 
vani and Volta. 

We have also seen (435) that electricity exhibits in a striking 
manner phenomena of attraction and repulsion, because it 
has two opposite states, one called positive electricity and the other 
negative electricity, and that electricity is a polar force with posi- 
tive polarity and negative polarity (449). 

It has also been stated that bodies charged with like elec- 
tricities repel each other, while two bodies of opposite electrical 
polarities attract each other (440). 

558. No chemical reaction takes place without the develop- 
ment of electricity. It is also known that chemical reactions are 
essential to the production of voltaic action. The energy of the 
electric current is proportionate to the energy of the chemical 
action, and the direction of the one is dependent upon the 
direction of the other. 

559. Electrolysis. — A great number of compounds can be 
decomposed into their immediate constituents by means of 
electricity. This is called electrolysis. The various compounds 
which can be decomposed by electrolysis are called electrolytes. 

560. Electrolytic decomposition resolves the constituents of 
the electrolyte into two groups, one of which is attracted to the 
negative pole of the battery, the other passing to the positive 
pole. 

561. The same current of electricity, transmitted succes- 
sively through different electrolytes, decomposes each in the 
proportion of their respective chemical equivalents. 

The energy of the electric current is proportionate to the 
energy of the chemical action which produces it. 



CHEMISTRY. 135 

562. When a chemical compound is decomposed by an elec- 
tric current, the matter attracted to the positive pole is said to 
be electro- negative, and that attracted to the negative pole is 
electro-positive . 

563. The foregoing facts point strongly to a law of oppo- 
sites in chemistry analogous to the law of opposites which is so 
strikingly manifest in the phenomena of electricity. 

564. Electro-chemical Polarity. — Radicals are of two 
opposite kinds as to the quality of their chemism, namely, posi- 
tive and negative radicals. Positive radicals unite with negative 
radicals, and negative radicals unite with positive radicals ; but 
one positive radical does not unite with another positive radi- 
cal ; no radical unites with another radical of the same electro- 
chemical polarity. 

565. Positive radicals are those which are attracted to the 
negative pole in electrolysis 

They form compounds with the negative radicals. 

566. Negative radicals are those which are attracted to 
the positive pole in electrolysis. 

They unite with positive radicals to form chemical com- 
pounds. 

567. Electro-chemical Theory. — The phenomena of chem- 
ism have been attributed to electrical attraction between atoms 
and between radicals. 

That strong grounds for such an hypothesis exist is sufficiently evident 
from the foregoing. There are, however, a large number of compounds 
which do not seem to be susceptible of electrolytic decomposition. 

The electro-chemical theory, and the idea of simple and compound rad- 
icals which is inseparable from it, do not so directly and plainly account for 
substitution, which results in changes within the radical, leaving the external 
behavior of the latter unaffected. 

Yet, until a better hypothesis shall have been presented, the obviously 
intimate relations between electricity and chemism are recognized, simple 
and compound radicals are referred to as relatively electro-positive or electro- 
negative, chemical combination is regarded as dependent upon the opposite 
electro-chemical properties of atoms and compound radicals, and the general 
chemical character and conduct of compounds are supposed to be determined 
by the electro-chemical characters and relations of their constituents. 



136 CHEMISTRY. 

Berzelius assumed that atoms were endowed with electric polaiity and that 
when two substances combine chemically their opposite electricities neutral- 
ize each other. This electro-chemical relation between acid-forming and base- 
forming simple or compound radicals applies to both inorganic and organic 
chemistry. 

568. Molecules formed by the union of strong electro-posi- 
tive radicals with strong electro-negative radicals offer greater 
resistance to change than other molecules. 

Very complex molecules, containing a large number of atoms, 
and composed of several different compound radicals, are more 
frequently unstable than those of more simple structure. 

569. But the terms " positive " and " negative," as applied 
to radicals, are only relative terms, for any one radical may be 
electro-positive with reference to some and electro-negative to 
other radicals of other kinds. 

Thus when nitric anhydride, which is a compound of nitrogen and oxy- 
gen, is decomposed by an electric current, its nitrogen is collected at the 
negative pole and its oxygen at the positive pole of the battery; but when 
ammonia, a compound of nitrogen and hydrogen, is similarly decomposed, 
the nitrogen passes to the positive pole, the hydrogen going to the opposite 
electrode. 

Sulphur is found to be electro-positive in sulphuric anhydride, a compound 
of sulphur and oxygen, but negative in its compounds with the metals. 

570. The metals are, as a rule, electro-positive. 

Sulphuric acid is hydrogen sulphate. The hydrogen in it is positive; 
but zinc is relatively a stronger positive radical and therefore takes its place 
when zinc is put into the acid. 

571. Silver is separated from a solution of silver nitrate by metallic 
lead, the lead taking the place of the silver in the solution. If the separated 
silver be filtered out and a piece of copper put in the solution of the lead 
nitrate, the lead will in turn be separated out by the copper, and the copper 
can be displaced in a similar way by either iron or zinc. 

572. The Electro-chemical Series. — Berzelius arranged 
the elements known in his day into a series according to their 
relative electro-chemical position, beginning with the strongest 
electro-negative element and ending with the strongest electro- 
positive element. Each element in the series is positive toward 
any element preceding it, and negative to any element below it. 
An abbreviation of it is given here: 





CHEMISTRY. 




Negative end — 


Atoi?iic weight. 


Oxygen II. 


16. 


Sulphur II, IV, VI. 


3 2 - 


Nitrogen I, III, V. 


14. 


Fluorine I. 




19. 


Chlorine I to VII. 
Bromine I to VII. 


► Halogens. 


35-45 
80. 


Iodine I to VII. 


126.85 


Phosphorus I, III, V. 


3i. 


Arsenic I, III, V. 


75. 


Chromium II, IV, VI. 


5 2 - 


Boron III. 


1 1. 


Carbon II, IV. 


12. 


Antimony III, V. 


120. 


Silicon IV. 


28.4 


— Hydrogen I. + 


-1. 


Gold I, III. 1 


197.3 


Platinum II, IV. Noble 
Mercury II. | metals. 


i95- 


200. 


Silver I, III. 
Copper II. 


108. 


63-4 


Bismuth III, V. 


209. 


Tin II, IV. 


119. 


Lead II, IV. 


207. 


Cobolt II, IV. 


59- 


Nickel II, IV. 


58-7 


Iron II, IV, VI. 


56. 


Zinc II. 


65.3 


Manganese II, IV, VI. 


55- 


Aluminum IV. 


27. 


Magnesium II. 


24-3 


Calcium II, IV. \ Alkaline 


40. 


Strontium II, IV. > earth 


87.6 


Barium II, IV. ) metals. 


137. 


Lithium I. -\ 
Sodium I, III. ( Alkali 
Potassium I. Ill, V. J metals - 


7. 

23- 

39- 


Positive end 4- 







137 



138 CHEMISTRY. 

573. Upon an inspection of the preceding table it will be found that 
oxygen is the strongest electro-negative element, with sulphur as second; and 
that potassium is the strongest electro-positive element (of the more common 
elements) with sodium as second. 

Oxygen forms with the negative elements (above hydrogen) acid forming 
oxides; with hydrogen it forms an absolutely neutral oxide, water; and with 
the positive elements (below hydrogen) it forms basic oxides. The com- 
pounds of the halogens with hydrogen are in several respects like the true 
acids. The compounds formed by sulphur with the other elements are analo- 
gous to those formed with them by oxygen. Oxygen and sulphur together 
form an oxide which produces (with water) the strongest acid known — sul- 
phuric acid. Oxygen and sulphur are dyads and the halogens are monads. 
The polyvalent negative elements, which are typically represented by nitrogen 
and carbon, are remarkable for the great number of compound radicals which 
they form with oxygen and hydrogen. 

Hydrogen and oxygen form water. But no less remarkable is the com- 
pound radical (HO) called hydroxyl, formed by one atom of each of these 
wonderful elements. Hydroxyl is contained in all acids, bases and alcohols. 

Arsenic, chromium and antimony (above hydrogen) are of a metallic 
character, but nevertheless form acids. 

Below hydrogen we find first gold and platinum which are very weak 
positive elements. The polyvalent elements bismuth and tin possess analo- 
gies with nitrogen and carbon, respectively, and form acids as well as bases. 

At the lower end of the series we have the strongest base-forming metals. 

574. The student should study this chapter again after he has learned 
the remaining chapters on chemistry, that he may recognize the fact that there 
is a self-evident intimate connection between the electro-chemical character 
of the elements on the one hand and their valence and atomic weights on the 
other. 

But the student must not suppose that he can employ the electro-chem- 
ical series as a safe guide in pre-determining the course of chemical reactions, 
or the relative electro-chemical character of compound radicals. An intelli- 
gent advanced student may often find satisfactory explanations of estab- 
lished facts by studying such tables as this; but all students must bear in 
mind at all times that ascertained facts stand both before and after theories, 
however attractive and really helpful the theories may be. Facts lead to 
theories, and theories in turn lead to other facts; but experimental science 
discovers facts independently of theory, and new theories are evolved which 
supplement, modify, or even supplant previous theories, while the facts stand. 
Only the learned and experienced may make, apply, analyze, and unmake 
theories. Students, however, should learn to understand accepted funda- 
mental theories, and their relations to the facts of experience, as far as they 
can. 



CHEMISTRY. 1 39 

CHAPTER XXVIIi. 

FIXED COMBINING PROPORTIONS AND THE ATOMIC THEORY. 

575. A vast number of chemical compounds have been 
examined, made, and unmade. Weighed quantities have been 
decomposed into their constituent elements, and the respective 
weights of these elements also ascertained and found to account 
for the whole. The same elements in the same proportions 
have also been put together again and caused to unite, the 
product being not only the same compound which had before 
yielded these elements when it was decomposed, but the weight 
of the product has been found to be exactly the same as the 
sum of the weights of the elements. Substances have been 
composed and decomposed in the same manner, and the factors 
and products weighed, without dealing with elemental mole- 
cules, and the results have been as absolute and invariable. 
Hence, nothing is lost in any chemical reaction, whether the 
reaction be synthetical or analytical. 

576. Water has been repeatedly decomposed. It has been 
invariably found to yield by its decomposition two elements, 
oxygen and hydrogen, and nothing else. Water has also been 
repeatedly made out of oxygen and hydrogen, and can be made 
of nothing else. Thus it has been conclusively proven that 
water is composed of hydrogen and oxygen. 

Numerous other substances have been decomposed and 
composed, many times over, and have been proven, analytically 
and synthetically, to consist invariably of the same elements. 
In no case has a different result been reached. Hence, any given 
kind of matter always contains the same elements 

577. It has been further demonstrated that water con- 
tains its oxygen and hydrogen invariably in the proportion of 
88.89 P er cent, by weight of the oxygen and ii.n per cent, by 
weight of the hydrogen. In other words ioo pounds of water 
always contains 88. 89 pounds of oxygen and n. 11 pounds of 
hydrogen. 



140 CHEMISTRY. 

If 88.89 pounds of oxygen and 11. 11 pounds of hydrogen be made to unite 
by chemism, the product is exactly 100 pounds of water. If any more than 
88.89 pounds of oxygen be used' with ri.ii pounds of hydrogen, all of the 
excess of oxygen above the 88.89 pounds will remain as still oxygen, but 100 
pounds of water will be formed; if less oxygen is used, a corresponding quan- 
tity of hydrogen will be left over, and a correspondingly smaller amount of 
water will be obtained. 

Hydrochloric acid is composed of 1 pound of hydrogen and 
35.45 pounds of chlorine, making 36.45 pounds of the acid ; and 
chlorine and hydrogen do not unite in any other proportions. 

If you try to combine 2 pounds of hydrogen with 35.45 pounds of 
chlorine you will have just I pound of hydrogen left over, etc. 

When calomel is decomposed and its constituent elements 
weighed it is found that 235.45 pounds of calomel contain 200 
pounds of mercury and 35.45 pounds of chlorine. 

If you combine 200 pounds of mercury with 35.45 pounds of chlorine, you 
will get just 235.45 pounds of calomel. But if you combine 200 pounds of 
mercury with 70.9 pounds of chlorine, you will not get calomel at all ; you will, 
however, get just 270.9 pounds of corrosive sublimate. 

Numerous other substances have been decomposed and 
produced with the result that the proportions of the component 
elements have been found to be invariable. In no case have 
the results been otherwise. Therefore all chei?iical compounds con- 
tain fixed proportions by weight of their component elemen 

578. But it happens frequently that two elements combine 
with each other in more than one ratio. In every such case, 
however, the product is a different substance whenever the pro- 
portions of the component elements are different; and the 
proportions necessary to form any particular substance are 
invariable. 

579. The metal manganese unites with oxygen in five differ 
ent proportions, as follows: 

55 pounds of Manganese unites with 16 pounds of oxygen. 

55 " " " " 24 

55 •' » <• << 32 » 

5 5 « «< « « 48 « 

55 " .'•' " " 56 



CHEMISTRY. 141 

If you now divide the pounds of oxygen in each case by the 
smallest number (16), you get the quotients i, i%, 2, 3, and 

Nitrogen unites with oxygen also in five proportions : 

14 pounds of nitrogen unites with 8 pounds of oxygen 
14 " " " " 16 " 

14 " " " '« 24 

14 " " " 32 

14 " " " 40 

If you again divide the number of pounds of oxygen by the 
smallest number (8), you will get 1, 2, 3, 4 and 5. 
Chlorine forms four oxides : 

709 pounds of chlorine unites with 160 pounds of oxygen. 
709 " " " " 480 " " 

709 " " ' " 800 " " 

709 " " "1,120 " " 

Divide the pounds of oxygen as before ■ the quotients are 1, 

3, 5 and 7- 

Three chlorides of manganese are known: 

550 pounds of manganese unites with 709 pounds of chlorine. 
550 " " " " 1,063.5 

550 " " ' 1,418 

Divide the pounds of chlorine as before the oxygen and you 
get the numbers 1, 1% and 2. 

Compare these tables with each other and you will further 
find that 550 pounds of manganese unites with 160 pounds of 
oxygen, but with 709 pounds of chlorine; that 709 pounds of 
chlorine also unites with 160 pounds of oxygen. 

580. The simplicity of these proportions is found to extend 
to all chemical compounds. How is it to be accounted for? 

If it be assumed that the elements are not divisible without 
limit, but that each element consists of indivisible particles hav- 
ing a fixed weight, that assumption will explain it all satisfac- 
torily No other theory has ever been proposed which does 
account for the fixed combining proportions observed in all 
chemical compounds. 



142 CHEMISTRY. 

581. It has been stated that it takes 8, 000 ,000,000 molecules of water to 
make a particle of water of sufficient size to be seen by the aid of one of the 
best modern microscopes. 

Sir William Thomson says: " If we conceive a sphere of water of the size 
of a pea to be magnified to the size of the earth, each molecule to be magnified 
to the same extent, the magnified structure would be coarser grained than a 
heap of small lead shot, but less coarse-grained than a heap of cricket-balls." 

It has been estimated that the mean diameter of molecules is so small that 
if 500,000 of them were placed in a row, the row would be only yo^ts mcn m 
length. It has also been said that the molecules of hydrogen are about 
Tnnnnnro" °f an i ncn a P art from each other. Each molecule of hydrogen con- 
tains two atoms. 

But these dimensions are beyond intelligent comprehension. Atoms are 
so small that their diameter and absolute weight can not be determined, and 
for purposes of argument we may as well assume that they weigh pounds as 
that they weigh an infinitesimal fraction of a milligram. The relative weights 
of atoms are believed to be correctly determined. 

582. If we assume, then, for argument's sake, that an atom 
of hydrogen weighs 1 pound, an atom of oxygen 16 pounds, nitro- 
gen 14 pounds, chlorine 35.45 pounds, manganese 55 pounds, and 
mercury 200 pounds, and that these atoms are indivisible — then 
the definite combining proportions observed in the examples 
given in paragraphs 577 and 579 will not only become intelligi- 
ble, but they could not be otherwise than fixed. 

Peroxide of hydrogen will be obtained when 1 pound of hydrogen forms 
molecules with 16 pounds of oxygen; but 2 pounds of hydrogen forms water 
with 16 pounds of oxygen; 16 pounds of oxygen unites with 14 pounds of 
nitrogen to form nitrogen dioxide; 14 pounds of nitrogen unites with 3 pounds 
(3x1) of hydrogen to form ammonia; 14 pounds of nitrogen unites with 106.35 
pounds (3x35.45) of chlorine forming nitrogen chloride; 3 pounds of hydrogen 
and 106.35 pounds of chlorine unite to form hydrochloric acid; 106.35 pounds 
of chlorine united with 55 pounds of manganese will form manganic chloride; 
55 pounds of manganese unites with 16 pounds of oxygen forming manganous 
oxide; 16 pounds of oxygen unites with 200 pounds of mercury to form mer- 
curic oxide; and 200 pounds of mercury unites with 35.45 pounds chlorine to 
form calomel, or with twice that amount of chlorine to form corrosive subli- 
mate. 

583. The Atomic Theory. — On account, then, of the fixed 
combining proportions (577 and 579) it is assumed that all matter is 
divisible into small particles called atoms which are themselves indivisible 



CHEMISTRY. 143 

having fixe a weights (580 and 582). This theory was proposed by 
Dalton. 

584. Atomic Weights, — The smallest weight of any ele- 
ment which can enter into the formation of a compound is its 
atomic weight. Atomic weights are expressed in hydrogen 
units; the relative weight of any atom as compared to the 
weight of the atom of hydrogen (H = 1), therefore expresses 
its atomic weight. 

Practically the smallest relative quantity by weight which 
has been found in the various compounds of an element is 
assumed to represent its atomic weight. This is the quantity 
by weight which unites with or can take the place of one atom 
of hydrogen. 

Whether or not the numbers called atomic weights actually represent the 
relative weights of atoms, they serve to express truthfully the definite and 
multiple proportions in accordance with which all compounds are formed. 

The molecular weight being known and also the number of 
atoms in the molecule the atomic weight is found by dividing 
the molecular weight by the atomicity of the molecule. 

585. Dalton's Law of Multiple Proportions — When- 
ever any two ele?nents combine in more than one proportion, the several 
compou?ids formed by these elements co?itain simple multiples of the 
atomic weights of both constituents. 

Thus if A and B unite in several different proportions, their 
atoms unite in the numerical ratios of 1 to 1, or 1 to 2, or 1 to 3, 
or 1 to 4, or 1 to 5, or 1 to 6, or 2 to 2, or 2 to 3, or 2 to 4. or 2 to 
5, or 2 to 6, or 2 to 7, or 3 to 4, or 3 to 5, or 3 to 7, or some 
other simple ratio. 

586. Dulong and Petit, in 1819, proposed the law that all 
atoms have the same capacity for heat. • 

In other words, it requires exactly the same amount of heat to raise the 
temperature of any atom one degree, without reference to its kind. 

Their proposition was based upon a series of investigations 
by which it became evident that a simple proportion exists 
between the specific heats and the atomic weights of the elements. 
These were found to be inversely proportional. 



144 CHEMISTRY. 

587. Specific heat is the relative quantity of heat necessary 
to raise the temperature of one weight unit of any substance 
one thermal degree. 

Specific heat is expressed in units of the specific heat of 
water, which is taken as the thermal standard. Thus the quan- 
tity .of heat necessary to raise one weight unit of water one 
degree is the specific heat of water, and being chosen as the 
standard of comparison it is == 1. 

■ But mercury requires only yf^ffo as much heat as water 
does to raise the same quantity of it one thermal degree, and, 
therefore, the specific heat of mercury is 0.0319. 

588. Investigations by Neumann and Regnault, in 1831, 
proved that the specific heats of compounds are inversely propor- 
tional to their molecular weights. 

589. Thus, the specific heat of elements is inversely as their 
atomic weights, and the specific heat of compounds inversely 
as their molecular weights. 

After further investigations by Regnault and others, with a 
great variety of compounds, it was concluded that all atoms, free 
or combined, have the same capacity for heat. 

These valuable discoveries afforded a new means of finding 
or verifying atomic and molecular weights. 

590. Deduction of Atomic Weight from Specific Heat. — 
The atomic weights of elements may be verified by examining 
the specific heats of their solid compounds. 

When the specific heat of any elementary body is multiplied by its atomic 
weight the product is a constant number. Owing to the unavoidable liabili- 
ties to error in such difficult determinations, the specific heats and the atomic 
weights found by the best methods known are not absolutely correct, and 
hence the product of the atonic weight by the specific heat varies somewhat, 
but the mean is 6.40. Whenever, therefore, the product varies considerably 
from that mean, one or both factors are assumed to be wrong; and should 
the product be only one-half of 6.40, or should it be twice 6.40, the inference 
would be that the atomic weight used is double or one-half of the actual. 

591. Atomic Heat. — The number obtained by multiplying 
the specific heat of any element by its atomic weight is called 
its atomic heat. 



CHEMISTRY. 



145 



As already stated, it is near 6.4. All elements are assumed to have the 
same atomic heat under certain conditions. 

[The molecular heat divided by the number of atoms contained in the 
molecule will also give the atomic heat.] 

592. The atomic heat of any element (6.4) divided by its specific heat will 
give its atomic weight; and the atomic heat divided by the atomic weight will 
give the specific heat. The specific heat multiplied by the atomic weight gives 
the atomic heat. 

593. Molecular Weight. — The molecular weight of any 
substance, or the weight of its molecule, is the sum of the 
weights of its constituent atoms. It is, therefore, found by- 
adding these together. 

594. Molecular Heat. — The number obtained by multiply- 
ing the specific heat of any compound by its molecular weight 
is called its molecular heat. It is the sum of the atomic heats of 
the atoms it contains. 

The molecular heat of any compound divided by the number of atoms 
contained in the molecule will give as a quotient the mean of the atomic heats 
of the elements, which, with rare exceptions, is about 6.4 (590) 

595. The number of atoms contained in any molecule may, therefore, be 
readily ascertained if its specific heat and molecular weight are known; for if 
the molecular heat is divided by 6.4 (the atomic heat) the quotient is the num- 
ber of atoms in the molecule. It is of course also found by dividing the 
molecular weight by the atomic weight. 

596. The specific heat of a substance may be found by dividing the molec- 
ular heat by the molecular weight. 

597. Combination by volume in simple proportions. Gay 

Lussac found that gases always combine in simple proportions 
by volume, and also that the volume of the product in the gas- 
eous state bears a simple relation to the volumes of the con- 
stituents. 

One volume of hydrogen unites with one volume of chlorine, producing 
two volumes of hydrochloric acid; two volumes of hydrogen unite with one 
volume of oxygen, producing two volumes of water-vapor; three volumes of 
hydrogen and one volume of nitrogen unite to form two volumes gaseous am- 
monia; etc. 

As elements combine in fixed proportions by weight, and, in 
the gaseous state, also in fixed proportions by volumes, it fol- 
lows that the weights of equal volumes of all gases bear the 
same relation to each other as do the combining weights of the 



146 



CHEMISTRY. 



elements, and if the atomic theory is correct the number of atoms 
contained in a given volume of any gas bears a simple relation to the 
number of atoms contained in the same volume of any other gas. 

598. In paragraph 582 it was shown that the relative com- 
bining weights, or atomic weights, of the four most important 
caseous elements are as follows: 

Hydrogen 1 

Nitrogen 14 

Oxygen 16 

Chlorine . 35.45 

When the weights of equal volumes of these gases are com- 
pared it is found that the above figures, representing their 
atomic weights, also express the relative weights of equal vol- 
umes. Thus one quart of nitrogen weighs 14 times as much as 
a quart of hydrogen, a quart of oxygen weighs 16 times as 
much as a quart of hydrogen, and a quart of chlorine gas 35.45 
times as much as a quart of hydrogen. 

As the specific weight of any kind of matter in a gaseous 
state, called its vapor density, is expressed in hydrogen units, the 
specific weight of hydrogen being taken as 1, we find that the 
vapor densities of hydrogen, nitrogen, oxygen and chlorine are 
exactly expressed by their atomic weights. 

599. Avogadro's Law. — The simple relations between the 
atomic weights and vapor densities of the elements of course 
appear also when the molecular weights are compared with the 
vapor densities, for the molecules of the elements are made up 
of a small number of atoms and the molecular weight is the 
sum of the weights of the atoms. Thus: 





ELEMENT. 


Vapor 
Density. 


Atomic 
Weight. 


Molecular 
Weight. 


Hydrogen 






1 1. 


16 


2 
28 


Oxygen 




16 


32 



Chlorine 



If comparisons be made of the weights and vapor densities 
of compound molecules, the same simple relations are found: 



CHEMISTRY. 



147 



Compound. 



Molecular 
Weight. 



Water 

Hydrochloric Acid . 
Sulphur Dioxide. .. 

Ammonia 

Marsh-gas 

Chloroform 




Avogadro accordingly proposed the hypothesis: Equal vol- 
umes of all gases contain the same number of molecules. 

600. If the molecular weight of any substance be divided 
by the vapor density (expressed in hydrogen units), the quotient 
should always be 2. The vapor density multiplied by 2 should 
give the molecular weight; and the molecular weight divided by 
2 should give the vapor density. 

[But Crafts and Meyer reduced the vapor density of iodine by heating 
until it was but one-half of the normal, or only one-fourth of the accepted 
molecular weight. That makes it appear as if iodine was then in an atomic 
condition.] 

601. It is easily shown that the molecuie of hydrogen con- 
tains at least two atoms, and for good reasons it is assumed that 
tbe number does not exceed two. 

Hydrogen having been chosen as the unit ot atomic weight, 
its molecular weight is 2, and if Avogadro's hypothesis is applied 
it is found that the molecular weight of any substance coincides 
with its vapor density multiplied by 2. 

It follows that the vapor density of any substance is expressed by one- 
half its molecular weight. 

602. As it follows from the atomic hypothesis that the num- 
ber of atoms contained in any elemental molecule is obtained 
by dividing the molecular weight by the atomic weight, 
therefore : — The atomic weight of all elements having diatomic 
molecules (2 atoms in each molecule) coincides with the vapor 
density; if the molecule contain but one atom the atomic weight 
is equal to twice the vapor density; in elements with triatomic 
molecules (3 atoms in each molecule) the atomic weight is equal 
to two-thirds of the vapor density; in elements with tetratomic 
molecules (4 atoms in each molecule) the atomic weight is equal 



148 CHEMISTRY. 

to one-half of the vapor density; and in elements with hexa- 
tomic molecules (6 atoms in each molecule) the atomic weight 
is equal to one-third of the vapor density. 

603. If it be assumed that one measure of hydrogen contains 1,000 mole- 
cules of hydrogen, one measure of oxygen contains the same number (599). 
Two measures of hydrogen, containing 2,000 molecules, would contain 4.000 
hydrogen atoms, and one measure of oxygen would contain 2,000 oxygen 
atoms, for the molecules of hydrogen and oxygen have both been found to be 
diatomic. The total number of atoms, then, contained in the two measures of 
hydrogen and one measure of oxygen would be 6. coo. When combined 
they form two measures of water vapor. According to Avogadro's law these 
two measures must contain the same number of molecules as the two measures 
of hydrogen, or 2,000. Now, as these 2.000 molecules of water were formed 
out of 4000 atoms of hydrogen and 2,000 atoms of oxygen, there must be 2 
atoms of hydrogen and 1 atom of oxygen in each water molecule, which is 
exactly what the molecule of water has been shown by other means to contain. 

The fact that 2 measures of hydrogen and 1 measure of oxygen form only 
2 measures of water vapor, is accounted for by the fact that the water molecules 
contain 3 atoms each while the hydrogen and oxygen contain only 2 atoms 
each 

1 volume of Hydrogen and 1 volume of Chlorine produce 2 volumes of 
Hydrochloric Acid gas 

2 volumes of Hydrogen and 1 volume of Oxygen produce 2 volumes of 
Water vapor. 

3 volumes of Hydrogen and 1 volume of Nitrogen produce 2 volumes of 
gaseous Ammonia. 

Hydrochloric acid is diatomic, and, therefore, requires only two volumes of 
diatomic elements to produce the same number of molecules. 

The molecule of water is triatomic, and, therefore, requires three volumes 
of diatomic elements to produce the same number of molecules. 

Ammonia is tetratomic, and, therefore, requires four volumes of diatomic 
elements to produce the same number of molecules. 



CHEMISTRY. I49 

604. Table of Atomic Weights used in this book. 
( H=I -) 

The names of elements occurring in pharmacopceial, medicinal chemicals 
are printed in heavy-faced type. 



Name. 



Aluminum. . 
Antimony. . . 

Arsenic 

Barium 

Bismuth — 

Boron 

Bromine — 
Cadmium 

Caesium 

Calcium 

Carbon 

Cerium 

Chlorine 

Chromium. . 

Cobalt 

Columbium 1 ) 

Copper 

Didymium 2 ) . 

Erbium 

Fluorine. . . . 

Gallium 

Germanium . 
Glucinum 3 ). . 

Gold 

Hydrogen 4 ). . 

Indium 

Iodine 

Iridium 

Iron 

Lanthanum. . 

Lead 

Lithium 
Magnesium . 
Manganese. 
Mercury 



Symbol 



Al 

Sb 

As 

Ba 

Bi 

B 

Br 

Cd 

C s 

Ca 

C 

Ce 

CI 

Cr 

Co 

Cb 

€u 

Di 

Er 

F 

Ga 

Ge 

Gl 

Au 

H 

In 
I 

Ir 

Fe 

La 

Pb 

Li 

Mg 

Mn 

Hg 



Atomic 
Weight. 



27. 
120. 

75. 
137. 
209* 

11. 

79.8 

111.5 

132,7 

40. 

12. 
140. 

35.4 

52. 

58.6 

93.7 

63.2 

142. 

166. 

19. 

70. 

72.3 
9. 
196.7 
1. 

113.6 
126.5 

192.5 

56. 

137.9 

206.4 

7. 

24.3 

55. 
1 200. 



Name. 



Molybdenum 

Nickel 

Nitrogen 

Osmium 

Oxygen .... 

Palladium. . . 
Phosphorus . 

Platinum. . . . 

Potassium . . 

Rhodium. . . . 
Rubidium . . . 
Ruthenium. . 
Samarium . . . 
Scandium . . . 
Selenium. . . . 

Silicon 

Silver 

Sodium 

Strontium. . . 
Sulphur — 

Tantalum . . . 
Tellurium . . . 
Terbium 
Thallium. . . . 
Thorium .... 

Tin 

Titanium. . . . 
Tungsten. . . . 
Uranium 
Vanadium. . . 
Ytterbium. . . 

Yttrium 

Zinc 

Zirconium. . . 



Symbol. 



Mo 

Ni 

N 

Os 



Pd 

P 

Pt 

K 

Rh 

Rb 

Ru 

Sm 

Sc 

Se 

Si 

Ag 

Na 

Sr 

S 

Ta 

Te 

Tb 

Tl 

Th 

Sn 

Ti 

W 

U 

V 

Yb 

Yt 

Zn 

Zr 



Atomic 
Weight. 



96. 

58.6 

14. 
190.3 

16. 
106.4 

31. 
194.3 
39. 
103.5 

85. 
101.4 
150. 

44. 

79. 
28.3 
107.7 

23. 

87.3 

32. 
182. 
125. 
159. 
203.7 
232. 
119. 

48. 
183.6 
239. 

51. 
172.6 

89. 

65.1 

90.4 



1) Has priority over Niobium. 2) Now split into Neo-and Praseo-Didymium. 
3) Has priority over Beryllium. 4) Standard, or basis of the system. 



150 CHEMISTRY. 

CHAPTER XXIX. 

VALENCE. 

605. We have said that atoms unite with each other to form 
molecules. All atoms of the same kind have the same chemi- 
cal saturating power ; that is, the quantity of the chemism of any- 
one atom is exactly the same as the quantity of the chemism of 
any other atom of the same kind. One atom has f he same com- 
bining value as another atom of the same kind. 

It is also found that one kind 'of atoms may have the same 
combining value or saturating power as atoms of a certain other 
kind. Thus, chlorine atoms and hydrogen atoms have the same 
combining value, so that one. atom of chlorine combines with 
one atom of hydrogen, both atoms being thereby saturated, so 
that not more than one atom of each kind can unite, and so that 
no other atom of any kind can unite with one atom of chlorine 
and one atom of hydrogen together. This equality of combin- 
ing power, or chemical saturating capacity, or atomic value, or 
combining value, is also shown by the atoms of potassium and 
chlorine, by calcium and oxygen, silver and iodine, zinc and sul- 
phur, boron and nitrogen, etc. In all these cases one atom of 
one kind unites with one atom of the other kind forming a 
molecule incapable of combining with any other atom or radi- 
cal. The chemism of the atoms of the molecule is, therefore, 
exhausted, saturated, satisfied, or neutralized. 

606. But an atom of chlorine has only one-half the value of 
an atom of calcium, for two atoms of chlorine are always 
required to saturate (or form a molecule with) one atom of cal- 
cium. One atom of oxygen has twice as great combining power 
as an atom of potassium, and twice the value also of an atom of 
hydrogen, for one atom of oxygen will satisfy at once one atom 
of each of potassium and hydrogen. One atom of nitrogen 
demands three atoms of hydrogen — no more, and no less. 

If we use the letter H to represent an atom of hydrogen, O 
to represent an atom of oxygen, N to represent an atom of 
nitrogen, C to represent an atom of carbon, and append numerals 



CHEMISTRY. 151 

to represent any number of atoms exceeding one, we shall be 
able to write the molecular formulas (630) of hydrochloric acid, 
water, ammonia, and marsh-gas. 

HC1 • H 2 H 3 N H 4 C 

Hydrochloric Acid Water Ammonia Marsh-gas 
These formulas show that if the combining value of the hydro- 
gen atom is expressed by 1, then the value of the oxygen atom is 
2, that of the nitrogen atom is 3, and that of the carbon atom 4. 

607. Radicals (519) unite with each otherin accordance with 
their relative combining or saturating power, which is called 
their valence. One or two atoms of one kind may, apparently, 
be capable of saturating one or two, three, four, five, six or 
seven atoms of another kind; or tw r o atoms of one kind may 
saturate three or five atoms of another kind. The same is true 
of compound radicals. 

Thus, one atom of hydrogen binds one other atom of hydrogen; but one 
atom of oxygen binds two atoms of hydrogen; one atom of nitrogen satu- 
rates three atoms of hydrogen; one atom of carbon satisfies four of hydrogen; 
and, while the atoms of chlorine and hydrogen are of equal value (as one 
atom of either binds one atom of the other), an atom of tantalum is of equal 
value with five atoms of chlorine; one atom of tungsten satisfies six atoms 
of chlorine; and the atomic value of chlorine in one of its compounds with 
oxygen appears as if it were seven times that of hydrogen. 

608. Valence is also called " atomic value,'' "quantivalence," 
"equivalence" [and sometimes also "atomicity"*]. 

609. Valence is expressed in hydrogen units. Hydrogen 
has been adopted as the standard of comparison for this pur- 
pose because the atom of hydrogen has a smaller valence than 
any other atom except those having the same value as itself. 

Therefore the valence of a radical may also be said to be rep- 
resented by the number of atoms of hydrogen which it satis- 
fies, or equals in combining power, or for which it can be 
exchanged. 

Hydrogen, being the unit, has a valence of one; any other 
radical uniting with, or capable of taking the place of, two atoms 

* The term atomicity has also been used to express the number of atoms 
contained in an elemental molecule (471). 



152 CHEMISTRY. 

of hydrogen has the valence 2; a radical which takes the place 
of, or satisfies, three atoms of hydrogen, has a valence expressed 
by the number 3, etc. 

610. Many elements and radicals do not unite with hydrogen; but they 
do unite with other radicals whose valence has been ascertained, and the 
valence of all radicals must be determined, not with reference to their hydro- 
gen compounds merely, but to their compounds generally, and especially with 
regard to their most important and best known compounds, whatever these 
may be. Thus, not only hydrogen compounds, but also oxides, chlorides and 
other molecules must be studied in order to correctly determine the valence 
of any element or compound radical. 

611. Artiads and Perissads. — Radicals whose valence is 
expressed by an even number, as 2, 4, or 6, are called artiads; 
while radicals of an uneven valence, as 1, 3, 5, or 7, are called 
perissads. 

612. The artiads are more numerous than the perissads. 
Hydrogen, and all other radicals having the same valence, are 
called monads, and are univalent; radicals which unite with or 
replace two hydrogen or chlorine atoms are called dyads and are 
bivalent; those that satisfy or replace three hydrogen or chlorine 
atoms are called triads and are trivalent; those equal in value to 
four hydrogen or chlorine atoms are tetrads and quadrivalent; 
radicals whose atomic value is five are called pentads, and they 
are quinquivalent; those whose valence is six are hexads and sexi- 
valent; and radicals with an atomic value of seven are heptads 
and septivalent. 

613. The valence of chlorine is 1, because 1 atom of chlo- 
rine will unite with and saturate 1 atom of hydrogen, or will 
replace it. Chlorine is, accordingly, like hydrogen, a monad and 
univalent. Iodine, bromine and fluorine are also monads for the 
same reasons. Potassium, sodium, lithium and silver are monads, 
too, because 1 atom of any oneof them will take the place of 1 
atom of hydrogen, and because either of them will unite with 
and saturate 1 atom of chlorine, iodine or bromine. 

Oxygen is a dyad, for 1 atom of it saturates 2 atoms of 
hydrogen. 

Negative nitrogen is a triad, because 1 atom of it will satisfy 
3 atoms of hydrogen. 



CHEMISTRY. 



Carbon has the valence of a tetrad, for i atom of it saturates 
4 atoms of hydrogen. 

For similar reasons other radicals are pentads, hexads or 
heptads. 

No radical has a highervalence than eight, and the two high- 
est valences (seven and eight) are comparatively rare. 

614. Radicals of a higher atomic value than that of hydro- 
gen, or radicals having more than one free bond, are called 
polyvalent radicals. Thus all atoms and compound radicals 
except monads are polyvalent. In comparing the structures of 
compound radicals and of binary and ternary molecules with 
each other, this term is convenient. 

Radicals having the same valence may be called equiv- 
alent. Thus potassium and hydrogen are equivalent atoms, 
both being univalent: zinc and oxygen are equivalent, for both 
are dyads. 

615. Bonds. — The valence units or affinities of atoms are 
sometimes, for convenience, called bonds. Thus, a monad or 
univalent atom has one bond; a dyad or bivalent atom has two 
bonds; a triad or trivalent atom has three bonds; a tetrad or 
quadrivalent atom has four bonds; a pentad or quinquivalent 
atom has five bonds; a hexad or sexivalent atom has six bonds; 
and a heptad or septivalent atom has seven bonds. 



Any atom which saturates or replaces 



j Has the following- i - ,. . 
number of bonds, j i:> cauea a 



And is 



1 atom of hydrogen or chlorine. 

2 atoms 



1 bond. 


Monad, 


Univalent. 


2 bonds. 


Dyad, 


Bivalent. 


3 


Triad, 


Trivalent. 


4 " 


Tetrad, 


Quadrivalent. 


5 " 


Pentad, 


Quinquivalent. 


6 " 


Hexad. 


Sexivalent. 


• 7 M 


Heptad, 


Septivalent. 



616. We might liken the atoms to coins, each having a definite value corre- 
sponding with the combining power. Monads may be likened to one-cent 
coins, dyads to two-cent coins, triads to three-cent coins, tetrads to four-cent 
coins, etc. As a two-cent coin is worth two one-cent coins, so a dyad atom is 
equal to two monad atoms; as it takes three one-cent pieces, or one two-cent 
and one one-cent piece to equal one three-cent piece, so does it take three 



154 CHEMISTRY. 

monad atoms, or one dyad and one monad to equal one triad; and as three 
two cent pieces have the same value as two three-cent pieces, so are two triad 
atoms equal to three dyad atoms, etc. • 

617. Variable Valence. — But the valence of elements is 
not always constant. Indeed very few of the elements seem to 
have a constant valence. Hydrogen and oxygen, which are the 
most remarkable and important of all elements, are assumed 
to have a constant valence. 

It was shown that (579) nitrogen and manganese have each five differ- 
ent oxides, or compounds formed by them with oxygen. 

618. Among the examples of variable valence we find: 

Nitrogen appears to be trivalent in forming ammonia because in that 
molecule 1 atom of nitrogen is united to 3 atoms of hydrogen ; while in a 
molecule of ammonium chloride 1 atom of nitrogen is united to 4 atoms of 
hydrogen, and I atom of chlorine besides, thus appearing to have in this case 
a total valence of 5. 

Phosphorus unites with 3 atoms of hydrogen to' form phosphine, and is 
then apparently a triad ; but when 2 atoms of phosphorus unite with 5 of 
oxygen the phosphorus would seem to be a pentad, for each oxygen atom has a 
valence of 2. 

Sulphur unites with two atoms of hydrogen and is then bivalent; but 
one atom of sulphur also unites with two atoms of oxygen and then it seems 
to be a tetrad ; and in the sulphuric acid molecule it appears as if it were a 
hexad. 

619. In some notable instances it appears as if variable valence depends 
upon the electro-chemical polarity. 

Thus sulphur \s positive toward oxygen, but negative toward all other ele- 
ments, and you will find that negative sulphur is always a dyad, while sul- 
phur united to oxygen (positive sulphur) presents the higher valences of four 
or six. 

Nitrogen is negative toward hydrogen but positive toward oxygen, so 
that we have negative nitrogen in ammonia but positive nitrogen in nitric 
anhydride (569). The negative nitrogen is a triad, but nitrogen united to oxygen 
may apparently have a valence of either one, three, or five. In nitric acid the 
nitrogen seems to be a pentad. And if a molecule of ammonia be brought in 
contact with a molecule of hydrochloric acid, the nitrogen of the ammonia not 
only changes its valence from that of a triad to that of a pentad, but it also 
changes its electro-chemical polarity from negative to positive. 

Phosphorus, like the nitrogen, is negative in its union with hydrogen, 
and then always trivalent, but it is positive in the formation of its oxides and 
compound radicals with oxygen and then may have, apparently, one, three or 
five valence units. 



CHEMISTRY. 



*55 



Chlorine is always univalent when it acts as an electro-negative radical, as 
in all chlorides, but the molecular formulas of its oxides and acids indicate 
higher valences for the positive chlorine. 

[In certain cases it has been observed that the valence of an element may 
be changed by heat.] 

620. It has been found that the valence of an atom never 
varies by a single valence unit, but always by two units, or by a 
multiple of two units. 

Thus an atom which exhibits a valence of 1 in one of its compounds, 
may in other compounds show a valence of 3, or 5, or 7, but never 2, 4, or 
6; and another atom exhibiting in one case a valence of 2 may in other cases 
show a valence of 4 or 6, but never 1, 3, 5 or 7. 

621. It has been sought to explain this fact on the assump- 
tion that the true valence of any atom is its highest apparent 
valence, and that this maximum vale?ice may be diminished by 
the mutual saturation of pairs of its bonds (615). 

To illustrate this partial self-saturation of atoms we will pict- 
ure a series of atoms with bonds representing their respective 
valences: 



o-okV 




MONAD. DYAD. 



TRIAD. TETRAD. PENTAD. HEXAD. HEPTAD. 



Or, they may be represented as follows, since the direction 
in which the bonds are extended is, of course, immaterial, and 
neither of these pictures can be likenesses of actual atoms: 



0-0=00= one 



The mutual saturation of pairs of bonds may be represented 
as follows: 




HEPTADS CHANGED 
TO PENTADS. 



HEPTADS CHANGED 



TO TRIADS. 



#CH 

PENTADS CHANGED TO 
TRIADS. 



(2xo= 



TRIADS CHANGED TO 
MONADS. 



15^ CHEMISTRY 





OCTAD CHANGED TO TETRAD, AND TETRADS CHANGED TO 

HEXAD TO DYAD. DYADS. 

Thus, if this assumption be accepted, a heptad can change to a pentad by 
the mutual saturation of two of its bonds, or it can become a triad by the 
mutual saturation of two pairs of its bonds, or it may even become a monad 
by the mutual saturation of six of its bonds in pairs. A hexad may become a 
dyad by the pairing of four bonds, or a tetrad if only two of its bonds be 
paired off. 

But an artiad can never become a perissad, nor can a perissad change to 
an artiad. 

In other words, no atom can at one time present an even number of bonds 
and at another time an odd number. 

622. In view of the variable valence of atoms it is difficult 
to classify the elements according to their valence, beyond a 
separation of the artiads from the perissads. 

The following table is arranged according to the maximum 
valences of the respective elements. The comparatively rare 
and unimportant elements are omitted from this table, and in 
all cases where the ruling valence differs from its maximum va- 
lence, the ruling valence of the element, or that valence which it 
plainly exhibits in its most important and stable compounds, 
is shown by Roman numerals in brackets : — 

Table of Atomic Values of the Elements (according to 
the maximum valence): 

Monads (univalent, or with one bond ): 
Hydrogen. 
Negative Chlorine. 
" Bromine. 
" Iodine. 
Dyads ( bivalent or with 2 bonds ) 
Oxygen. 

Negative Sulphur. 
Magnesium. 
Zinc. 



CHEMISTRY. 157 

Cadmium. 

Mercury. 

Copper. 
Triads ( trivalent, or with 3 bonds ): 

Boron. Sodium ( I ). 

Negative Nitrogen. Silver ( I ). 

Negative Phosphorus. Gold. 

" Arsenic. 

Tetrads ( quadrivalent, or with 4 bonds ): 

Carbon. Calcium (II). 

Silicon. Strontium ( II). 

Tin. Barium (II). 



Aluminum. 

Platinum. Lead (II). 

Pentads (quinquivalent, or with 5 bonds): 
Positive Nitrogen (also I and III). 
Phosphorus (III). 
" Arsenic ( III ). Potassium ( I). 

" Antimony ( III ). 
Bismuth (III). 

Hexads (sexivalent, or with 6 bonds): 
Positive Sulphur (also IV). 
Chromium ( II ). 
Manganese ( II ). 
Iron (Hand IV). 

623. The complexity of molecules depends mainly upon 
the relative valence of their component atoms. This will be 
easily understood when we remember that all the valence units 
in the molecule must be mutually tied, combined, satisfied, or 
saturated. 

624. Valence has no relation to the energy of chemism 
called chemical affinity. 

Chlorine, though a monad, has a powerful chemical affinity, whereas 
carbon which is quadrivalent is entirely inactive at ordinary temperatures. 
The trivalent element, phosphorus, on the other hand, is more energetic in its 



f ; CHEMISTRY. 

chemical combining power than either quadrivalent carbon, trivalent nitrogen, 
bivalent snlphnr, or univalent hydrogen (521). 

625. A" ::~c:ur.i nAziA live ir r.vir:i: e viAn:e: a-. r; varnhA 
alence see-. 5 ::> occur only in what is cailed inorganic chemistry. 

626 As A-z: 15 :he ziuses ::' va: :ze rerr.i r. unk-.r^r. :he 

. /. " • 5 : :h e ~ :i. : : ~ : : : : a : . : r. : r. us: : : r. : r.ue : : ir pear Ass 5 : ~ 7. . e : he r. : h e y 
::::::;■ ire :r. r e 1 . : : y A. :h e rr. e ar. : : ~ e — e ~ 1 5 : re~ e ~A er .hi: :h e 
::' many eArr.enzs :s varAzA :ha: :he mix mam vi'.er.ie ::' in a:_rr. may r.:t 
:e ;s zzmmzr. vaAnze r.zr ::s vaAnze in i:s m:s: imyzr.an:. :r i:s 21:5: 

B_: :r. ah uses ~here ~ne kn:~ :he raAzaA enzerinz: .:.:: 1 mzAzaA. 
arA aA: :he:r resyezzive vaAnzes ~e :ir. rea z.'.y : : r.s ::_ :: ::.: : mzAzznar 
ArmiAs I en A. :ises -here eAmer.zal raAzaA ire zznzemei i: is rraz::- 
zame :: zase :he mz AzAar zzrmiAs z: rr. :s: :: :ie rr.r :r:ir.: zzmyzurAs 
i::r. vaAnze and :: Aarn :; — rAe ArmiAs i:::r: nz. 



CHAPTER XXX. 



::-::m::a: :;::a:::v 



627. Chemical Notation is the system of representing 
at: — s an d :u Ae tales :y means ::' syrr.btls and fhrnzuAas. 

Atoms are represented by symbols; molecules by formulas. 

628. Symbols -re ^zbreviations or signs consisting of let- 
ters. In many cases the symt :'. consists of but one letter, and 
in all such cases that letter is the initial of the Latinic name of 
the element. In cases where the Latinic names of two or more 
elements begin with the same letter, an additional letter from 
that name is added to make the necessary distinction. The 
additional letter thus used may be the second letter in the name, 
or some other letter. 

The svmbols, therefore are abbreviations of the Latinic 
names :: the elements, ar.d tensist ::' but :ne :r r.v; letters. In 



CHEMISTRY 



T 59 



symbols consisting of two letters only the first is a capital 
letter. 

No two atoms are represented by the same symbol. 

Thus Boron is represented by B, Carbon by C, Hydrogen by H, Nitrogen 
by N, Oxygen by O, Potassium by K (the Latinic name of it is Kalium), 
etc. 

As B is used for Boron, Ba is the symbol for Barium, Bifor Bismuth, and 
Br for Bromine. C being the symbol for Carbon, Ca is used for Calcium, CI 
for Chlorine, and Cu (from Cuprum) for Copper. Having given the sym- 
bol N to Nitrogen, it was necessary to make the symbol for Nickel Ni, and 
for Sodium Na (from Natrium). 

629. To represent one atom the symbol is sufficient alone. 
To represent an elemental molecule the symbol is accompanied 
by a small Arabic numeral to the right of the symbol, the num- 
ber expressing the number of atoms contained in the molecule, 
thus:— H 2 , K 2 , 2 , P 4 ,Cl 2 ,etc. 

630. Formulas are combinations of symbols with numer- 
als to express the kinds and numbers of atoms entering into the 
molecules of matter. 

The formulas for elemental molecules, as shown in the pre- 
ceding paragraph, are simple because elemental molecules each 
contain but one kind of atoms. 

The formulas for compound molecules are constructed out 
of at least as many symbols as there are different kinds of atoms 
in the molecule which is to be represented, and after each sym- 
bol is placed the numeral expressing the numbers of atoms if 
more than one. 

The positive radical is always placed before the negative 
radical. 

As the molecule of potassium iodide contains one atom of the positive 
potassium and one of the negative "iodine, its molecular formula must be 
written KI; but the molecule of water is composed of two atoms of hydrogen 
and one atom of oxygen, and its formula must, therefore, be H 2 0; a mole- 
cule of hydrochloric acid is HC1, for it contains one atom of each of hydrogen 
and chlorine, and the molecular formula for hard soap (sodium oleate) is 
NaCi b H 33 02, because it contains one atom of sodium, eighteen atoms of car- 
bon, thirty-three atoms of hydrogen and two atoms of oxygen. 

631. Single molecules are represented by the respective 



l6o CHEMISTRY. 

molecular formulas. Thus HC1 represents not only hydrochlo- 
ric acid, but also one single molecule of hydrochloric acid. 
When two or more molecules are to be written, a large Arabic 
numeral is placed in front (or to the left) of the molecule. 

Thus three molecules of hydrochloric acid must be written 3HG; two 
molecules of water must be written 2H0O; and 5KI stands for five molecules 
of potassium iodide; 4NH3 represents four molecules of ammonia, and 
2NaC 1? H 33 2 means two molecules of sodium oleate. 

632. When a group of atoms or a compound radical is to 
be multiplied, the symbols of the atoms or the formula of the 
radical must be enclosed in brackets and the numeral placed 
outside below and to the right. 

Thus, Ca(OH) 2 represents calcium hydrate, which contains one atom of 
calcium, two atoms of oxygen and two atoms of hydrogen; but as each 
hydrogen atom is united directly to one of the oxygen atoms and the com- 
pound thus contains two groups of the radical HO, and as this radical is 
united to the calcium atom by means of bonds from the oxygen, the formula 
is correctly written Ca(OH) 2 . The formula Pb(N0 3 ) 2 represents lead nitrate, 
which contains the group X0 3 twice. 

[Entire molecules are occasionally multiplied in the same manner — that 
is, by enclosing the molecular formula in brackets and placing the multipli- 
cator or numeral outside, below, to the right.] 

633. A large numeral placed in front of any formula applies 
to all that follows it up to the first period; except that if that 
numeral is placed directly in front of brackets enclosing a form- 
ula the number multiplies all that is contained within those 
brackets. 

In 2K2CO3 the first figure 2 applies to all that follows it as a whole. 

In 2K2CO3. 3H2O the first figure 2 applies to K 2 C0 3 , and to nothing 
more, and the large figure 3 applies to the formula H 2 0. But in 3 (2K 2 C0 3 . 
3H2O), and in (2K2CCV 3H 2 0) 3 the figure 3 outside the brackets applies to all 
within. 

In 4MgC0 3 . Mg (OH) 2 .5HoO the figure 4 applies only to MgC0 3 ; the 
inferior figure 2 in Mg (OH) 2 applies only to the group OH, and the figure 5 
applies to H 2 0. 

In 3Pb(C 2 H 3 2 )2 the figure 3 in front applies to the entire formula which 
follows, viz., to Pb(C 2 H 3 2 ) 2 . 

In 6(NaC 2 H 3 2 3H2O) the figure 6 applies to all that is contained within 
the brackets. 

In 2(Fe 2 (C 6 H 5 0:)2. 6H 2 0) the large figure 2 in front applies to all that 



CHEMISTRY. l6l 

follows, while the inferior figure 2 in (C^HoOt)? applies only to the group 
CeHjOv, and the large figure 6 only to H ; 0. 

In Fe 4 (P 2 07) 3 . 4(Na 3 C 6 H 5 7 ). SH ; 0. we see that there are four atoms of 
iron, 3 groups of the radical PoO-, then 4 times Xa 3 C 6 Hs07, and 8 molecules 
of water. 

Thus it will be seen that in representing the formulas of some complex 
molecules it is necessary to use both large and inferior numerals, more than 
one pair of brackets, and brackets within brackets. 

634. The valence of elements is indicated by Roman numerals at the 
top and a little to the right of the symbol, thus: — Hi means univalent hydro- 
gen; O'i means bivalent oxygen; N"» means trivalent nitrogen; Xv, quinquiv- 
alent nitrogen; C' v means quadrivalent carbon; S"» bivalent sulphur; S iv » 
quadrivalent sulphur; S vi i sexivalent sulphur; Ta v . quinquivalent tantalum; 
and \Y V >, sexivalent tungsten. 

635. Chemical Equations. — Chemical decompositions and 
reactions are conveniently and clearly represented by the num- 
bers and formulas of the molecules which are decomposed in the 
reaction and the numbers and formulas of the molecules result- 
ing by it. This is done in the form of an equation. 

The molecules which take part in the change are placed on 
the left of the sign =, and the molecules of the product or 
products on the right. 

Thus: 

Fe 2 -}-2l 2 =2FeI 2 ; 

2 Na 2 HP0 4 — H 2 0=Na 4 P 2 7 ; 

CaCl 2 + Na 2 C0 3 =CaC0 3 4-2NaCl; and 

Hg 2 (NO s ) 2 . 2H 2 0=2HgO+N 2 4 +2H 2 0. 

636. The number of molecules taking part in a chemical 
reaction varies according to the respective valences of the rad- 
icals concerned, or the atomic rearrangement produced. 

In many cases only one molecule of each reagent is required 
to complete the reaction; but in other cases several molecules 
of each may be necessary. 

One molecule of silver nitrate and one molecule of potassium iodide will 
react upon each other to form one molecule of silver iodide and one molecule 
of potassium nitrate, thus: — 

AgN0 3 +KI=AgI+KN0 3 . 

In the preparation of solution of chloride of antimony, one molecule of 



162 



CHEMISTRY. 



sulphide of antimony reacts with six molecules of hydrogen chloride, thus:— 

Sb 2 S 3 +6HCl=2SbCl 3 + 3H 2 S. 

In the preparation of sodium valerate the reaction involves three mole- 
cules amylic alcohol, two molecules potassium bichromate and eight mole- 
cules sulphuric acid, thus: — 

3C3H ia O + 2K 2 Cr 2 O7+8H 2 SO 4 =3C 3 H l 0O 2 + 2K 2 SO 4 + 2(Cr 2 SO4)3)-r-iiH a O. 

637. Both Sides must be Equal. — Both members of the 
chemical equation must contain the same kind and number of 
atoms, and the sum of the molecular weights on one side of the 
equality sign must be equal to the sum of the molecular weights 
on the other side. 

638. The student must learn the use of symbols and how to write for- 
mulas and equations by actual practice. This can best and most safely be 
accomplished with the aid of a competent teacher, who will point out any 
errors. All that is necessary for the present is that the student shall thor- 
oughly memorize the symbols employed to represent the most important ele- 
ments, which are as follows : 

Element. Symbol. Element. Symbol. 

Hydrogen. H. Strontium. Sr. 

Fluorine. F. Barium. Ba. 

Chlorine. CI. Magnesium. Mg. 

Bromine. Br. Zinc. Zn. 

Iodine. I. Cadmium. Cd. 

Oxygen. O. Aluminium. Al. 

Sulphur. S. Cerium. Ce 

Carbon. C. Chromium. Cr. 

Silicon. Si. Manganese. Mn. 

Tin. Sn. Iron. Fe. 

Boron. B Nickel. Ni 

Nitrogen. N. Cobolt. Co. 

Phosphorus. P. Lead. Pb. 

Arsenic. As. Copper Cu. 

Antimony. Sb. Mercury. Hg. 

Bismuth. Bi. Gold. ' Au. 

Lithium. Li. Silver. Ag. 

Sodium. Na. Platinum. Pt. 

Potassium. K. Molybdenum. Mo. 

Calcium. Ca. Tungsten. W. 

The symbols of all known elements will be found on pages 112-113, and the 
origin of each symbol will also be found on the same pages, as the table there 
given includes the Latinic titles of all the elements (465) 

The memorization of the symbols of important elements is absolutely 
necessary before the student can make much progress in the study of 
chemistry. 

639. After the student has perused the whole number of pages devoted 



CHEMISTRY. 



i6t, 



to chemistry in this book he should return to a study of this chapter and learn 
it thoroughly. 

Much of what is contained in this chapter is at this stage unintelligible to 
the student; but after reading the next few chapters he should read this again. 



CHAPTER XXXI. 

THE ELEMENTS. 

640. General Review. — Of the seventy elements about four- 
fifths are metals, the remainder being called non-metallic elements. 
It is impossible, however, to draw the line absolutely between 
metallic and non-metallic elements, because several elements 
partake more or less of the characteristics of both classes, 
physically as well as chemically. 
641. The metals are: 

Molybdenum, 

Nickel, 

Osmium, 

Palladium, 



Aluminum, Erbium, 

Antimony, Gallium, 

Arsenic, Germanium, 

Barium, Glucinum, 

Bismuth, Gold, Platinum, 

Cadmium, Indium, Potassium, 

Caesium, Iridium, Rhodium, 

Calcium, Iron, Rubidium, 

Cerium, Lanthanum, Ruthenium, 

Chromium, Lead, Samarium, 

Cobalt, Lithium, Scandium, 

Columbium, Magnesium, Silver, 

Copper, Manganese, Sodium, 

*Didymium, Mercury, Strontium, 

642. The non-metallic elements are: 
Boron, Hydrogen, 

Bromine, Iodine, 

Carbon, Nitrogen, 

Chlorine, Oxygen, 

Fluorine, Phosphorus, 

* (Split into two metals.) 



Tantalum, 

Tellurium, 

Terbium, 

Thallium, 

Tin, 

Titanium, 

Tungsten, 

Uranium, 

Vanadium, 

Ytterbium, 

Yttrium, 

Zinc, 

Zirconium. — 57, 



Selenium, 
Silicon, 
Sulphur. — 13. 



164 CHEMISTRY. 

643. The preceding classification is wholy artificial and 
based upon external appearances and physical properties, espe- 
cially upon metallic lustre or want of it, tenacity or want of it, 
etc. 

It is true that in some instances elements which naturally fall 
into characteristic groups according to their chemical proper- 
ties and compounds are not separated; but in other instances well 
defined natural groups are broken by this artificial classification. 

644. Sometimes arsenic antimony, bismuth, and tellurium are classed 
with the non-metallic elements, the three first named because they are so 
closely related to nitrogen and phosphorus which are unquestionably non- 
metallic, and tellurium because it so much resembles sulphur in its chemistry. 
But if these metallic substances are to be classed with the non-metallic for 
chemical reasons, there are other metals, as tin, molybdenum and tungsten, 
which might with equal propriety be classed among the non-metals. 

645. State of Aggregation. — The metals, with but one 
exception, are solid. The exception is mercury, which is liquid 
under ordinary conditions, solid below — 40 C. ( — 40 F.), and 
vaporizes at +350 C. (662°. F.). 

Of the non-metallic elements boron, carbon, iodine, phos- 
phorus, selenium, silicon and sulphur are solids; bromine is a 
liquid; and chlorine, fluorine, hydrogen, nitrogen and oxygen 
are gases. 

646. Fusibility of the Solids. — All the metals are fusi- 
ble, some of them at temperatures below the boiling point of 
water, some only at extremely high temperatures, others between 
these extremes. 

Among the solid non-metallic elements boron, carbon and 
silicon are infusible. 

647. Volatility. — Mercury, potassium, sodium, zinc, magne- 
sium, cadmium and arsenic can be distilled; tellurium and anti- 
mony can be distilled only with a current of hydrogen. 

Of the non-metallic elements iodine, phosphorus, selenium, 
sulphur and bromine are vaporizable. 

648. Crystallization. — Many of the metals are crystalliza- 



CHEMISTRY. 165 

ble; the greater number of these form cubes or regular octo- 
hedrons; tellurium, arsenic and antimony crystallize in rhombo- 
hedrons of the hexagonal system. 

Bismuth, zinc, copper, lead, tin, silver and gold all crystal- 
lize. 

All the solid non-metallic elements are crystallizable. 

649. Opacity is given as one of the properties by which 
metals may be distinguished from the non-metallic elements. 
But gold in thin layers placed between two plates of glass trans- 
mits greenish light. 

Of the solid non-metallic elements boron, carbon (as char- 
coal, coal and graphite) iodine, selenium, silicon and sulphur 
are opaque; while phosphorus is translucent, and carbon as dia- 
mond is alone transparent. 

650. Lustre. — The metals possess a peculiar lustre, espe- 
cially when polished. Some metals have this quality in much 
higher degree than others. 

But boron, carbon (as diamond and as graphite), silicon, 
iodine and sulphur also possess a lustre. 

651. Color. — When in compact masses the metals have 
usually a white color with a more or less marked tendency 
toward grayish or bluish; but barium, calcium and gold have 
a yellowish or yellow color, and copper is reddish. 

In this respect the non-metallic elements vary greatly among 
each other and from the metals. 

652. Density. — The specific weights of about two-thirds of 
the metals exceed 5: but of the remainder several have specific 
weights below two. Of some of the heavy metals (674) the 
specific weights exceed 10, the heaviest being Platinum 21.5 and 
iridium 22.4. It is commonly stated that metals, as a rule, have 
higher specific weights than the non-metallic elements, but 
more than one-half of the non-metallic elements have specific 
weights ranging from 1.83 to 4.95. Really we can only say in 
this direction that the specific weights of two-thirds of the 
metals are higher than those of any non-metallic elements, and 
the specific weights of several aon-metallic elements are lower 



l66 CHEMISTRY. 

than those of any metals, while the specific weights of the greater 
number of the non-metallic elements are higher than those of 
the alkali-metals (676) and several of the alkaline earth metals 
(678). In fact, several elements which resemble the non-metallic 
elements more than they resemble metals in their chemical 
properties have higher specific weights than many undoubted 
metals which are chemically farthest removed from the non- 
metallic elements. 

653. Metals are relatively better conductors of heat and 
of electricity than non-metallic elements. But the metals 
exhibit these properties in a high degree only when in solid, 
compact masses; obtained in a state of fine division by precipi- 
tation they are far less effective conductors of electricity and 
heat. 

654. Tenacity, ductility and malleability are properties 
belonging to many of the metals, and to none of the non-metallic 
elements. But there are also many metals which do not possess 
these properties, as bismuth, antimony, arsenic, manganese, 
chromium, zinc, tungsten, molybdenum and vanadium. 

655. Solubility. — No metal is soluble in any simple solvent. 
Most metals are soluble chemically in the stronger acids, and 
some also in strong alkalies; others only in "aqua regia." 

Of the non-metallic elements boron, carbon and silicon are 
insoluble in all simple solvents; but iodine and bromine are 
soluble in alcohol and in glycerin; phosphorus, selenium and 
sulphur in fixed oils and carbon disulphide. 

656. Occurrence in Nature. — Gold, silver, mercury, copper, 
lead, bismuth, arsenic and antimony occur free or uncombined. 
The metals of the platinum group occur together in the so-called 
platinum ore and osmium-iridium, in a metallic state. Iron 
and nickel, in the free state, occur in meteors. No other metals 
occur uncombined. It is a]so to be observed that silver, mer- 
cury, copper, lead, arsenic, antimony, iron and nickel occur 
only in small quantities uncombined, and in much larger amounts 
in their native compounds. 

The most common forms in which heavy metals exist in nature 



CHEMISTRY. jCj 

is in chemical combinations with oxygen and sulphur, and less 
frequently with other non-metallic elements and compound 
radicals. 

Of the non-metallic elements carbon (as graphite and dia- 
mond), nitrogen, oxygen and sulphur are found uncombined. 
These are also found, and in much larger quantities, combined 
with other elements: carbon and nitrogen chiefly with non- 
metallic elements in organic substances; oxygen with hydrogen 
in water, with silicon in silica, with nearly all the metals, and 
with carbon and hydrogen in organic substances; while sulphur 
occurs mostly combined with iron, copper, lead, zinc and other 
. metals. Bromine, chlorine, fluorine and iodine (the " halogens ") 
occur combined with sodium and other metals; and the remain- 
der of the non-metallic elements chiefly combined with oxygen. 
Of all the seventy elements oxygen is the most abundant, 
then probably silicon, aluminum, iron, calcium, carbon and 
hydrogen. 

657. Alloys and Amalgams.— Some of the metals com- 
bine with each other, sometimes in definite proportions, forming 
even crystallizable compounds. The most interesting compound 
of this kind is one consisting of two atoms of antimony and 
three atoms of zinc. The chemical union of metals in definite 
atomic proportions, and in accordance with their valence, is 
attended with the evolution of heat, which is strong additional 
evidence that the union is a true chemical re-action. 

But mixtures of metals prepared by fusing them together, 
in proportions other than such as would be in accord with the 
atomic weights, are commonly employed in the mechanical arts, 
and they are called alloys. These alloys probably contain true 
chemical compounds of the metals, which, in a state of fusion, 
are soluble in (or miscible with) each other. That this is the 
case is indicated by the fact that when the molten mass is 
rapidly cooled a homogeneous mass in obtained; while, if the 
cooling be slow, the less readily fusible compounds may crys- 
tallize out, leaving the more fusible alloy still in a liquid state, 



l68 CHEMISTRY. 

so that, when the whole has become cold, the mass is not uni- 
form. 

A most striking property of alloys is the fact that their fus- 
ing points are lower than those of their constituents. 

Thus cadmium melts at 315 C. (599 ° F.), tin at 227°.8 C. (442° F.), lead 
at 325 C. (617 F.), and bismuth at 264 C. (507 F.); yet an alloy (Wood's) 
made of 1 to 2 parts of cadmium, 2 parts of tin, 4 parts of lead, and 7 to 8 
parts of bismuth melts at from 66° to 71 C. (i5o°.8 to I59°.8 F.). 

Arcet's alloy is made of 8 parts of bismuth, 5 parts of lead, and 3 parts of 
tin, and melts at 94°-5 C. (202 F.). 

Brass, bronze, gun metal, bell metal, German silver, type metal, pewter, 
britannia metal, solder, coin metal, and several other metallic substances are 
alloys. 

The alloys formed by mercury are called amalgams. 

658. But the alloys, although evidently consisting of true chemical com- 
pounds, retain the essential metallic characteristics of the constituents in a 
high degree, thus differing very greatly from other chemical compounds in 
which the characteristic physical properties of the component elements are 
generally obliterated. The alloys are the only chemical compounds formed 
by the metals with each other. 

659. The non-metallic elements, on the other hand, form with 
each other numerous chemical compounds of the most varied 
nature, and they also severally combine with the metals. When 
a non-metallic element combines with another non-metallic ele- 
ment or with a metal the compound formed is usually radically 
different from either of the elements entering into that com- 
pound. 

660. We have seen that the only compounds which metals 
form with each other resemble in their essential physical prop- 
erties the metals of which they are composed (658). They are 
solid, hard, opaque, lustrpus, tenacious, ductile, malleable, or 
brittle, according to the character of their component metals in 
these respects, and their color also is such as would naturally 
result by a mere physical mixture of the constituents. 

661. But when non-metallic elements enter into chemical 
compounds, the state of aggregation, density, consistence, color, 
solubility, and other physical properties of the compounds have 
apparently no relation to the properties of the component ele- 
ments (662). 



CHEMISTRY. j6p 

662. Oxygen and hydrogen are gases; they can be compressed to the 
liquid state only by the aid of tremendous pressure and extreme cold; but 
when they combine chemically with each other the compound formed is 
water. 

Carbon can not, by any means at present known, be converted into a 
liquid or a gas; it is infusible and fixed. But the compounds of carbon with 
oxygen, hydrogen and nitrogen, are gases, liquids and solids. 

Iodine is a bluish-black solid of a peculiar, penetrating odor; but its 
compound with hydrogen is a colorless gas having a very different odor. 

Carbon, in its ordinary condition, is a black solid; sulphur is a yellow 
solid; both are inodorous. But the compound of carbon and sulphur is a col- 
orless, offensively odorous liquid. 

Mercury is a bluish-white, shining liquid metal, and oxygen, a colorless 
gas: but they form two different compounds with each other, both solids, one 
of them either orange red, brick red or orange yellow, the other, grayish 
black. 

663. Numerous other examples might be given to illustrate the radical 
change of properties which follows chemical reactions in which the non-metal- 
lic elements are concerned. 

Indeed, it would seem as if these striking differences between the metals 
and the non metallic elements afforded reasons stronger than any others for 
the classification of the elements into metallic and non-metallic. Yet these 
striking distinctions, as far as they extend, are not lost by the more natural 
classification of the elements according to their chemical behavior and the 
character of their compounds, but are rather brought out more clearly. 

664. The fact that the properties of the elements bear some simple rela- 
tion to their atomic weights seems to be beyond doubt. It has been formu- 
lated in the conclusion that "the chemical properties of the elements are a 
periodic function of their atomic weights." The atomic weights in many 
instances differ by the number, 16, representing the atomic weight of oxygen 
(H=i), or by a number which is nearly a multiple of 16. It has also been 
shown that these simple differences are to be observed between the atomic 
weights of elements possessing many similarities in chemical behavior. 
Further, it has been found that in many natural groups of elements the 
atomic weight of one member is frequently one-half of the sum of two other 
members, etc. Many chemists have tabulated the elements in various ways 
to bring out these periodic co-incidences, in the hope of finding a true expla- 
nation of them. The most complete table of this kind is that of the Russian 
chemist, Mendeleeff. The properties which seem to bear such a periodic rela- 
tion to the atomic weights include: relative electro-chemical polarity, valence, 
specific weights, atomic volumes, specific heat, etc. Mendeleeff 's table is as 
follows: 



170 



CHEMISTRY. 






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CHEMISTRY. 171 

CHAPTER XXXII. 

OXYGEN, HYDROGEN AND SULPHUR. 

665. Oxygen (O; at. w. 1 6) is a colorless, odorless, taste- 
less gas, which constitutes over one-fifth of the weight of the 
air. 

One liter of 2 at o° C. and 760 mm barometric pressure 
weighs 143 Grams. 

Water is composed of 8 parts of oxygen and 1 part of hydro- 
gen, chemically united, nearly one-half of the weight of the rocks 
is oxygen, and a large proportion of oxygen is also contained in 
the earths and soils and in plants and animals. Its great abun- 
dance in nature is in itself sufficient evidence of its vast impor- 
tance. 

666. Preparation. — Certain compounds containing O are 
easily decomposed, giving up their O when heated, and these 
compounds are, therefore, utilized in making the 2 . The most 
common materials employed for that purpose are oxide of mer- 
cury, HgO, and potassium chlorate, KCIO3. Both part with all 
of their oxygen when heated: 2HgO=2Hg+0 2 and 2K00 3 = 
2KCI4-3O2. [When the potassium chlorate is mixed with about 
one-fourth of its weight of manganese dioxide (" black oxide of 
manganese") the decomposition progresses more quietly and 
evenly, although the manganese dioxide does not take part in 
the reaction.] 

667. Oxygen combines with all other elements except fluor- 
ine alone. Oxidation is the union of oxygen with other 
elements, or with compound radicals (804). Chemical combina- 
tion with oxygen, or oxidation, is one of the most common and 
important of chemical reactions. When oxidation is very rapid 
and accompanied by the evolution of heat and light it is called 
fire or combustion. Substances which take up oxygen and 
become chemically united with it are said to be oxidized. Oxidi- 
zation is necessary to the existence of plants and animals. 
Respiration is a process of oxidation. 

668. But although oxygen plays such an important role in 



172 CHEMISTRY. 

animal and plant life, and forms compounds with all other 
elements but one (667), it exhibits no great chemical energy 
at ordinary temperatures. 

669. The compounds formed by the union of positive radi- 
cals with oxygen are called oxides. 

670. When H is ignited the product of its combustion is 
water, H 2 0; the product of the combustion of S is the irritating 
gas S0 2 ; P, when burned, forms P 2 5 , which is a white solid; 
Mg when ignited burns with a brilliant flame, producing 
" magnesia," MgO; and three pounds of the metal will, when 
"consumed" by the fire, leave five pounds of ashes, consisting 
of the oxide; carbon, as charcoal or coal, forms C0 2 when its 
combustion is completed in a free supply of 2 , or CO if the 
supply of 2 is deficient; alcohol, oil, and other organic sub- 
stances, when burned, produce C0 2 and H 2 0. 

The most intense degree of heat obtainable by combustion 
is produced when a mixture of H2 and 2 in proper proportions 
is ignited. 

671. Ozone is a molecule of three oxygen atoms: ^_y o or 
3 . It has a peculiar odor, which is noticed sometimes in a 
place where lightning has just struck, or in a room where an 
electrical machine is in operation. Ozone has a powerful 
chemical energy, causing, at ordinary temperatures, the oxida- 
tion of metals which can not be oxidized by ordinary oxygen, 
decomposing potassium iodide, and destroying vegetable colors. 

672. Oxygen is the strongest electro-negative element. It 
is always bivalent. It is, therefore, capable of linking together 
the most strongly electro-positive metals with the strongest 
electro-negative elements, like sulphur, nitrogen, etc., to form 
neutral stable compounds called salts. The oxides of strongly 
electro-negative elements form acids (with water),- while the 
oxides of strongly electro-positive elements, as potassium, sodium, 
calcium, etc., form bases (with water). 

673. Oxygen, then, is present in all hydroxyl acids (884), 
bases (874), and oxy-salts (900). It may, therefore, be truly 
termed the principal salt-former, being the only constituent in 



CHEMISTRY. . £73 

the true salts (oxy-salts), and performing, in the formation of 
the salt molecule, the important function of uniting the positive 
to the negative radical. 

Oxygen is also present in several of the most important com- 
pound radicals, as in HO, CO, N0 2 , etc., and compound radicals 
containing O, but not H, are always negative. 

674. Hydrogen (H; at. w. 1) is a colorless, odorless, 
tasteless gas. It does not exist free. Its most abundant and 
wonderful compound is its oxide, called water, of which it con- 
stitutes one-ninth by weight. It is also present in most of the 
organic substances, animal or vegetable. 

One liter of H 2 at o° C, barometer at 760 mm, weighs 
0.08958 Gram (called 1 crith). It is the lightest of all gases. 

675. A mixture of H 3 and O s , when ignited, explodes with 
great violence, except when a current of the mixed gases issues 
from a tube through a small orifice, as in the oxy-hydrogen burner. 
The product is water. But water is decomposed by electrolytic 
action into its two component elements. 

676. Preparation. — H 2 is produced by the action of zinc 
upon sulphuric acid or hydrochloric acid : Zn-f-H 2 SO±= 
Zn S0 4 +H 2 and Zn + 2HCl=ZnCl 2 +H 2 . 

Hydrogen is also formed together with CO by the decompo- 
sition of water resulting when steam is passed over coal heated 
to an intense temperature : 

2H 2 0+C 2 =2CO + 2H 2 . This mixture of CO and H 2 is 
called fuel gas and water gas. 

677. H 2 is, at a high temperature, a powerful reducing 
agent ; that is, it has a strong affinity for oxygen, and, there- 
fore, removes O from oxides and other molecules. 

678. Water may be regarded either as the oxide of hydro- 
gen, H a O, or as hydrogen hydrate, HOH. It is colorless, 
odorless, tasteless and entirely neutral. At the ordinary tem- 
peratures it is liquid ; its boiling point is ioo° C. (212° F.), and 
its freezing point o° C. (32° F.). Its vapor is called steam, and 
congealed water is called ice. Its maximum density is attained 



174 CHEMISTRY. 

at 4° C. (39'. 2 F.). Its vapor density is 9 ; Sp. w. at 4 C. = 1; 
mol. w. iS. 

The wonderful oxide of hydrogen — water — does not form 
any salt ; but it forms acids with the acid-forming oxides, and 
bases with the base-forming oxides. 

Water is the most important of all solvents. 

679. Natural water — that contained in the ocean, lakes, 
rivers, springs, wells and clouds — is not pure. 

Sea wafer contains much salts. 

Spring water is called hard water because it generally contains 
calcium acid carbonate, and produces insoluble compounds with 
soap in washing. 

Well water is frequently contaminated with organic sub- 
stances, which are the products of decomposing animal or vege- 
table matter. 

Lake water and river water are often comparatively pure and 
soft, or nearly free from calcium compounds and other sub- 
stances. 

Rai?i water, collected after the air has been purified by the 
first part of the shower, and in such a manner that the water 
has not come in contact with roofs or other dusty or soiled 
objects, is the cleanest natural water obtainable. 

680. Distilled water, carefully made, is the only perfectly 
pure water. Natural water contains both volatile and fixed im- 
purities. When it is distilled the volatile constituents accompany 
the first portion of the water vapor ; the first portion of the dis- 
tillate is, therefore, rejected. The distillation is discontinued 
before all of the water has been vaporized, because there may 
be fixed organic substances present which might be decomposed 
by the heat when the water remaining in the still, flask, or retort, 
is but a small quantity. 

Distilled water must be used for all chemical and pharma- 
ceutical purposes where calcium compounds, chlorides, sul- 
phates, carbon dioxide, ammonia, and other impurities common 
to natural water are objectionable. 

681. Peroxide of hydrogen is H 2 2 , or H— O— O — H, or 



CHEMISTRY. 175 

HO united to OH. It is a colorless syrupy liquid, which acts 
as a powerful bleaching and oxidizing agent, because it is easily 
decomposed, giving up one-half of its oxygen, and thus becom- 
ing reduced to water. A solution of peroxide of hydrogen is 
used in medicine, its value being dependent upon the oxygen 
which is being constantly liberated in it by the decomposition 
of the peroxide of hydrogen. 

682. Hydrogen does not under ordinary conditions exhibit 
any marked affinity for other elements, except for chlorine and 
bromine ; but at high temperatures it has great affinity for 
oxygen and is, therefore, often employed as a reducing agent. 

683. Hydrogen is always univalent (612). In its chemical 
behavior it is radically different from oxygen. It stands in 
the middle of the electro-chemical series (572) separating the 
relatively negative from the relatively positive elements. It 
generally acts as an electro-positive radical, but in many mole- 
cules containing hydrogen all or part of that hydrogen may be 
replaced by oxygen, chlorine, and other negative radicals. 

The hydrogen atom is, therefore, a frequently occurring 
radical. Thus in HC1 it is positive, in KOH it is regarded as 
negative, and in HOH as both. It shares with oxygen the dis- 
tinction of forming many compound radicals, especially with 
quadrivalent and trivalent elements ; but there is this notable 
difference that the compound radicals containing oxygen are 
generally acid radicals while those containing hydrogen are 

basic. 

684. Although it maybe said that hydrogen occupies the neutral ground 
between the univalent radicals, chlorine at one extreme (strongly negative) 
and potassium at the other end (strongly positive), yet it has been recognized 
that hydrogen stands much closer to the metals than to chlorine. It has, 
indeed, been called the gaseous metal. An alloy of hydrogen with palladium 
has been made, and a medal consisting of that alloy, containing nine hun- 
dred volumes of hydrogen, was once produced. Later hydrogen was com- 
pressed by Pictet (at the close of 1877) into a steel-blue liquid; a portion of this 
liquid solidified, being deprived of its latent heat by the vaporization of another 
portion, and the solid pieces of hydrogen, striking the ground as they fell, 
produced a shrill metallic sound. 



176 CHEMISTRY. 

685. Hydrogen is contained in all acids as positive hydro- 
gen, and may be displaced from its position in the acid molecule 
by any other positive radical. It is contained in all bases as 
relatively negative hydrogen, and may be displaced from the 
molecule of a base by any other negative radical. In this 
respect then it acts wholly differently from oxygen, for the oxy- 
gen of an acid or a base is not thus displaced. Thus the hydro- 
gen in acids and bases is a relatively weak radical. 

686. With the halogens (696) hydrogen forms binary com- 
pounds called hydrogen acids, which have the strongly marked 
corrosive and sour properties of true acids (hydroxyl acids), and 
which form with the bases other binary compounds resembling 
the salts and called haloids. Hydrogen is displaced from its 
position in the molecule of hydrogen-acids by other positive 
radicals, for the hydrogen in hydrogen-acids as well as in 
hydroxyl acids is positive hydrogen. 

687. With nitrogen hydrogen forms a strongly alkaline body 
called ammonia — the very opposite of acids in its properties; 
while oxygen forms with nitrogen several oxides, one of which 
produces one of our strongest acids — nitric acid — when it reacts 
with water. 

688. Hydrogen and oxygen are, together with carbon and 
nitrogen, the most important elements in organic chemistry. 
But they play entirely dissimilar r61es. 

With carbon hydrogen forms many compounds which are 
even more neutral, or chemically indifferent, toward other sub- 
stances than the oxide of hydrogen. 

689. Among the compound radicals formed by hydrogen 
are HO, NH„ NH 2 , NH, HS, CH 3 , C 2 H 5 , CH 2 , CH^ C 3 H 5 , and 
numerous others. All compound radicals containing hydrogen 
but not oxygen exhibit electro-positive polarity. 

690. Sulphur (S ; at. w. 32.) is under ordinary condi- 
tions a yellow solid, odorless and tasteless, insoluble in water 
and in alcohol, but soluble in fixed and volatile oils. Melts at 
115 C; boils at 448 C. 



CHEMISTRY. 



177 



It occurs free as well as combined, its most important com- 
pounds being the sulphides (854) and sulphates (907). 

The sources of the sulphur of commerce are the native sul- 
phur and iron pyrites. 

Sulphur occurs in two forms — hard and soft. The soft 
plastic sulphur is obtained by heating the common sulphur at 
200. ° to 250. C. 

In commerce we find roll sulphur (" brimstone"), sublimed 
sulphur (" flowers of sulphur "), washed sulphur (U. S. P.), and 
precipitated sulphur. 

691. Like oxygen, sulphur is an artiad (611). The atomic 
weight of S is precisely twice that of O. 

At ordinary temperatures sulphur exhibits no marked chem- 
ical energy ; but at high temperatures it has a strong affinity 
for the metals, oxygen, and some other elements. 

The compounds formed by positive radicals with S. are called 
sulphides (854). 

692. Many of the compounds of sulphur are analogous to 
the compounds of oxygen. Thus the acid-forming oxides are 
to some extent paralleled by analogous sulphides, the base- 
forming. oxides are also represented by corresponding basic sul- 
phides, and there are sulphur salts which resemble the oxy- 
salts in structure, the only difference being that one series con- 
tains atoms of sulphur where the other series contains the same 
number of atoms of oxygen in the same relative position. 

The following oxygen compounds and sulphur compounds will suffice to 
show their analogy : 



Carbon Dioxide 


CO, 


cs 2 


Carbon Disulphide 


Hydrogen Oxide 


H g O 


HoS 


Hydrogen Sulphide 


Ferrous Oxide 


FeO 


FeS 


Ferrous Sulphide 


Calcium Oxide 


CaO 


CaS 


Calcium Sulphide 


Ferric Oxide 


Fe 2 3 


Fe 8 S 8 


Ferric Sulphide 


Arsenous Oxide 


AsoO s 


ASoSg 


Arsenous Sulphide 


Arsenic Oxide 


As 5 


As 2 S 5 


Arsenic Sulphide 


Sodium Carbonate 


Na„C0 3 


Na 2 CS 3 


Sodium Sulpho-carbonate 



In all these compounds, in which sulphur occupies a position analogous 
to that of the electro-negative oxygen, the sulphur acts as a dyad. But in all 



178 CHEMISTRY. 

molecules and radicals in which sulphur is united to oxygen, the sulphur thus 
playing the role of a positive element, it is apparently a tetrad or a hexad. 

■Selenium and Tellurium resemble sulphur in their chemistry. 

693. The oxides of sulphur are sulphurous anhydride, 
S0 2 , and sulphuric anhydride, S0 3 . 

Sulphurous anhydride, or sulphur dioxide, is formed when 
sulphur is burned in air, and is the " sulphurous vapor " observed 
in igniting sulphur matches, and which is so irritating to the 
air passages. Dissolved in water it forms sulphurous acid. It 
has strong bleaching properties. 

The sulphuric oxide, or sulphuric anhydride, or sulphur 
trioxide, is not so readily prepared ; but the acid it forms when 
brought in contact with water is familiar to us under the name 
of sulphuric acid, which is chemically the strongest of all acids 
and terribly corrosive. 

694. Sulphuric acid is prepared by first burning sulphur 
(or pyrites') to form S0 2 , which is conducted into a lead cham- 
ber, where it comes in contact with N 2 0± (generated separately), 
water vapor and air. The S0 2 is oxidized at the expense of 
the N 2 4 to S0 3 : 

2 S 2 + N 2 4 =2 SO3+ N 2 2 . 

The N 2 2 then takes up O from the air, forming N 2 4 
again : 

N 2 2 +0 2 =N 2 4 . 

The S0 3 forms sulphuric acid with the water : 

S0 3 +H 2 0=H 2 S0 4 . 

Sulphuric acid is one of the most useful of all the strong 
acids, because it decomposes -numerous other compounds on 
account of the strongly electro-negative polarity of the sul- 
phate radical. Other acids are thus prepared by decomposing 
their salts by sulphuric acid. 

The official sulphuric acid is nearly absolute H 2 S0 4 , being 
required to contain at least 96 per cent. It is an oily, colorless 
liquid of 1.840 sp. w. (water = 1). 

695. With hydrogen, S forms the colorless gas H 2 S, known 
as hydrogen sulphide, or sulphuretted hydrogen, or hydrosul- 



CHEMISTRY. 1 79 

phuric acid, or sulphydric acid. This gas has the odor of rot- 
ten eggs, and is poisonous when inhaled. It is soluble in 
water. Its principal use is as a chemical reagent for the pre- 
cipitation of the heavy metals from the solutions of their salts, 
which is possible because these sulphides are insoluble in 
water. 

It is prepared from ferrous sulphide by the action of sul- 
phuric acid : 

FeS + H 2 S0 4 =FeSO i + H 8 S. 



CHAPTER XXXIII. 



THE HALOGENS. 



696. The Halogens are a characteristic group of the four 
elements: fluorine, chlorine, bromine, and iodine. The chem- 
ical energy of fluorine is so intense that it has not been possible 
to study its properties in the free state. Chlorine is a gas, and 
is endowed with very energetic chemism. Bromine is a liquid 
and also energetic. Iodine is a solid and has strong chemical 
energy, too, although relatively weaker than that of the other 
halogens. They form, respectively, chlorides, bromides, and 
iodides with the metals. 

But in cases where one metal forms two different series of haloids, the 
most stable chlorides, relatively, are the higher (or-" ic ") chlorides, while the 
most stable iodides are the lower (or-" ous ") iodides, and the bromides do not 
exhibit any marked difference as between the higher and lower. 

697. The term "halogen" means salt-former. These elements are 
so called because they form with metals and positive compound radicals a 
class of compounds in many respects resembling the salts produced by the 
union of oxyacids with bases. They constitute a class of salt-formers very 
different from oxygen and sulphur. This is in some measure accounted for 
by the fact, that, while oxygen and sulphur are dyads, the halogens are 
monads. But when the dyad salt-formers are placed beside the monad salt- 
formers, with the atomic weights appended, the exhibit becomes intensely 
interesting. Here they are: 



l8o CHEMISTRY. 



Dyad Salt-Formers. 



Atomic Weight. 

Oxygen j6 

Sulphur 32 

Selenium 79 

Tellurium I25 



Monad Salt-Formers. 



Atomic Weight. 

19 Fluorine 

35.4 Chlorine 

80 Bromine 

127 Iodine 



698. Oxygen, we -have said, is the strongest electronegative element; 
we may add now that fluorine is the strongest electro-negative monad. 

No compound of oxygen and fluorine is known. 

As to the remaining three members of each group, it should be observed 
that the atomic weights of the middle members, selenium on one side and 
bromine on the other, are very nearly half of the sums of the other two, a 
coincidence which recurs in other groups of elements. It should also be 
remembered that these elements stand in their groups in exactly the same 
order as in the electro chemical series. 

699. Chlorine, and its fellow halogens, do not exhibit a strong affinity 
for oxygen, notwithstanding their energetic action upon metals and hydrogen 
compounds. This is significant. To induce chlorine to combine with oxygen 
it is necessary to strengthen the attraction between these elements by the 
presence of a strong base — or, in other words, to take advantage of the pre- 
disposing affinity (97) of that base for the united chlorine and oxygen. It is 
also to be observed that negative chlorine — the salt former — is always univa- 
lent, but the positive chlorine which enters into chemical union with oxygen is 
apparently \ as a rule, polyvalent. 

700. Chlorine. — (CI; at. w. 35.4) is a yellowish green gas 
of suffocating odor, soluble in water to the extent of 0.6 per cent, 
at about io°C. At 15° C. and under the pressure of four atmos- 
pheres it can be rendered liquid. Chlorine does not occur free, 
but it exists abundantly in the combined state in the chlorides 
of potassium and sodium. 

Chlorine gas is poisonous when inhaled. 
One liter of chlorine weighs 3.17 Grams. 

701. Preparation. — It is best prepared by the mutual 
decomposition of hydrochloric acid and manganese dioxide 
(black oxide of manganese) : Mn0 2 +4HCl=Cl 2 +MnCl 2 + 2 H 2 0. 

702. Chlorine forms four different oxides, namely: 
Cl 2 0=hypochlorous oxide or anhydride; 

. Cl 2 3 =chlorous oxide or anhydride; 
Cl 2 5 =chloric oxide or anhydride; and 
Cl 2 7 =perchloric oxide or anhydride. 



CHEMISTRY l8l 

These oxides form with water, respectively, hypochlorous, 
chlorous, chloric and perchloric acid. These acids are unstable. 

703. With hydrogen CI forms a gas called hydrochloric 

acid, or hydrogen chloride, the solution of which is one of the ' 

most important of the strong acids. This acid is prepared by 

decomposing sodium chloride (common salt) with sulphuric 

acid: 

NaCl+H 2 S0 4 =NaHS0 4 +HCl. 

Impure commercial hydrochloric acid is commonly called 
"muriatic acid." 

The hydrochloric acid of the Pharmacopoeia is a water solu- 
tion containing 31.9 per cent, of HC1. 

Other chlorides are referred to elsewhere (860). 

704. The affinity of chlorine for hydrogen is remarkable. It is capable 
of removing hydrogen atoms from organic molecules. Each molecule of 
chlorine consists of two atoms; one of these atoms unites with- the atom of 
hydrogen while the other chlorine atom usurps the former position of that 
hydrogen atom in the organic compound. In numerous cases the chlorine 
seems, indeed, to remove the hydrogen even from its combinations with 
oxygen, after which the oxygen, in its nascent state, vigorously attacks other 
substances present. 

''Bleaching powder," or "chlorinated lime" (generally 
misnamed "chloride of lime") contains as its only valuable 
constituent the unstable salt calcium hypochlorite, and the 
"solution of chlorinated soda" (or " Labarraque's solution ") 
contains sodium hypochlorite. These preparations are easily 
decomposed, yielding free chlorine, and their value depends 
upon the amount of Cl 2 they yield. 

705. Bromine (Br ; at. w. 79.85) is a dark, reddish-brown, 
heavy, volatile liquid, having an extremely irritating odor. 
When inhaled it is poisonous, and its vapor attacks the eyes and 
air passages dangerously. It must, therefore, be kept and 
handled with great care, and is usually put up in glass stoppered 
bottles imbedded in clay enclosed in a tin box. It is insoluble 
in water, but soluble in alcohol, ether, chloroform and carbon 
disulphide, and freely soluble in solutions of iodides and bromides. 

It occurs in the bromides of salt springs. 



1 82 CHEMISTRY. 

706. Preparation. — Bromide of potassium, sodium, or mag- 
nesium may be used as the material for the production of Br 2 , 
the salt being decomposed by passing the stronger electro- 
negative element chlorine into a water solution of the bromide : 
2KBr+Cl 2 =Br 2 + 2 KCl. 

707- A solution of hydrogen bromide, containing 10 per 
cent, of the HBr, is official under the name of hydrobromic acid. 
It is a strong acid, and may be made by decomposing potassium 
bromide with sulphuric acid, a mixture of these two substances 
being subjected distillation: KBr+H 2 S0 4 =KHS0 4 +HBr. 

The bromides are referred to elsewhere (866). 

708. Iodine (I ; at. w. 126.5) i s a crystalline, lustrous, 
blackish, brittle solid, having a peculiar penetrating odor. It is 
practically insoluble in water, but readily soluble in a solution 
of potassium iodide ; it is also soluble to the extent of nearly 10 
per cent, in alcohol, and less freely in fixed oils and in glycerin. 
Ether, chloroform and carbon disulphide dissolve I 2 rather freely. 

It liquefies at 113 C, and boils at 200 C; but violet vapors 
of iodine are produced when the I 2 is heated at much lower 
temperatures. 

Iodine occurs in the iodides of salt springs and sea water. 
It is prepared out of the ashes of sea-weeds which contain iodides. 

709. Hydrogen iodide, or hydriodic acid, is so unstable that 
its water solution can not be preserved from decomposition ; but 
the addition of a large quantity of sugar retards that decompo- 
sition and hence there is an official " syrup of hydriodic acid." 



CHAPTER XXXIV. 

THE NITROGEN GROUP AND BORON. 

710. Nitrogen (N; at. w. 14) is a colorless, odorless, taste- 
less gas, which constitutes four-fifths of the weight of the air. 
By extreme cold and pressure it can be rendered liquid. It is 
neither combustible nor a supporter of combustion. 



CHEMISTRY. 183 

Combined with other elements nitrogen is contained in 
albuminous substances, alkaloids, and certain other organic 
substances. 

One liter of nitrogen weighs 1.25 Grams. 

711. The oxides of N are five: 

N 2 = nitrogen monoxide. 

N 2 2 = " dioxide. 

N 2 3 = " trioxide. 

N 2 4 = " tetroxide. 

N 2 5 = " pentoxide. 
The trioxide and tetroxide are liquids; the others, gases. 
The trioxide is blue; the tetroxide, red; the others, colorless. 

N 2 is often called "nitrous oxide gas," or " laughing gas/' 
and is used as an anaesthetic by dentists. It is prepared by heat- 
ing dry ammonium nitrate: NH 4 N0 3 =2H 2 0+N 2 0. 

712. When nitric acid acts upon metals the acid-is usually 
decomposed, giving of N 2 2 ; this takes up more oxygen from 
the air, forming red vapors of N 2 4 . 

713. Nitrogen exhibits chemical properties wholly different 
from those of the dyad salt-formers, the monad salt-formers, 
and hydrogen. The fact that nitrogen is trivalent must, of itself, 
distinguish its chemistry from that of either oxygen, sulphur, 
hydrogen, or chlorine. 

Nitrogen is even more indifferent in its chemical combining 
energy than oxygen, sulphur, and hydrogen. It does not unite 
directly with other elements even at high temperatures. To 
compel the nitrogen atoms to separate from each other and 
unite with other elements unusual means are necessary; the 
chemical affinity must be re-inforced by such favorable condi- 
tions as the status nascens (542), predisposing affinity (548), etc. 
And the compounds of nitrogen, when formed, are generally 
unstable, decomposing readily, and sometimes with explosive 
violence. Heat is often sufficient to cause their decomposition. 
Hence, nitrates are effective oxidizing agents, and our most 
powerful explosives are nitrogen compounds. The nitrogenous 
substances in animal matter decompose rapidly. It is clearly 



184 CHEMISTRY. 

these very properties of nitrogen which render nitrogenous 
matters suitable materials. for the construction of certain animal 
tissues, nitrogen acting largely as a carrier of other elements and 
radicals. 

[A remarkable exception to the generally unstable character of nitrogen 
compounds is the peculiar compound formed of boron and nitrogen, BN.] 

714. The polyvalence and indifferent chemical energy of 
nitrogen are its ruling characteristics. By reason of these 
characteristics it forms, both with oxygen and with hydrogen, 
powerful compound radicals, in the formation of which the nitro- 
gen must be regarded as a passive agent. In forming compound 
radicals with oxygen the nitrogen is electro-positive, with hydro- 
gen electro-negative. 

The strongest compound radicals are formed by quinquivalent nitrogen, 
as might be expected. Ammonium, NH 4 , and nitryl, N0 2 , are examples. But 
even trivalent nitrogen forms strong radicals, as, for instance, cyanogen CN. 

715. The compounds formed by nitrogen with other non- 
metallic elements are singularly interesting. 

716. It does not unite directly with any metal. We have 
seen that with oxygen it forms no less than five different 
oxides; but the radical N0 2 which combines with itself to form 
N 2 4 , and with OH to form nitric acid, and which enters into 
numerous organic molecules possessing striking properties, is 
the most remarkable oxide. 

717. With hydrogen it forms the extraordinary substance 
which is so familiar to us under the name of ammonia. In this 
compound the nitrogen is the electro-negative radical, as we 
have stated. Ammonia unites directly with the acids, forming 
ammonium salts, the valence of the nitrogen rising at the same 
time from 3 to 5. A saturated compound of hydrogen with 
quinquivalent nitrogen (NH 5 ) does not exist. But NH 4 , NH 2 
and NH exist as powerful radicals. 

Ammonia should be written H 3 N instead of NH 3 , the hydrogen being the 
positive radical of the molecule. It is not nitrogen hydride, but hydrogen 
nitride. The alkaloids, which in small quantities are such valuable medicines 
and in larger quantities frequently so deadly in their effects upon plants and 
animals, are derivatives (843) of ammonia, retaining the nitrogen. 



# CHEMISTRY. ^5 

718. With sulphur nitrogen forms no stable compound, but 
only a violently explosive substance (N 2 S 2 ). 

With the halogens, also, nitrogen produces only extremely 
unstable molecules. 

719. With carbon nitrogen forms a very remarkable com- 
pound radical called cyanogen, which is capable of combining 
with itself as well as with other radicals. In its chemical rela- 
tions this compound radical conducts itself like the halogens, 
forming cyanides with the metals and other positive radicals. 
Cynanogen is extremely poisonous, the acid it forms with hydro- 
gen (HCN), called hydrocyanic acid (formerly called prussic acid), 
is also a terrible poison, and so are several of the other cyanides. 

720. Ammonia is prepared by double decomposition 
between calcium oxide ("quick-lime") and ammonium chloride: 
2NH 4 Cl+CaO=CaCl 2 + H 2 0-f 2 NH 3 . 

NH 3 is a colorless gas having an extremely pungent odor, 
highly caustic and poisonous when inhaled, and affecting the 
eyes and air passages so strongly that solutions of ammonia 
(called " water of ammonia") must be handled with caution. 
One liter of the gas weighs 0.762 Grams. The Pharmacopoeia 
contains one solution of ammonia containing 28 per cent, of 
NH 3 , and another containing 10 per cent. When N 1 ^ is 
dissolved in water, the solution may be properly regarded 
as containing ammonium hydrate: NH 3 + H 2 0=NH 4 OH. 

Ammonia water is largely employed in pharmaceutical 
chemistry as a convenient and effective alkali hydrate (874) 
for the precipitation of metallic hydrates, the neutralization of 
acids, etc. 

721. Nitric Acid is prepared from potassium or sodium 
nitrate by the action of sulphuric acid: NaN0 3 -+-H 2 S0 4 = 
HN0 3 + NaHS0 4 . It is a highly corrosive acid and extremely 
poisonous because of its destructive chemical action. 

The official nitric acid is a solution containing 69.4 per cent, 
of HNO s and having the sp. w. 1.42 (water=i.). 

This acid is used to dissolve metals (890) and as an oxidizing 
agent. 



1 86 CHEMISTRY 

722. Phosphorus and other polyvalent perissads.— Nitro- 
gen, phosphorus, vanadium, 'arsenic, antimony and bismuth are 
generally placed together in one group, called the nitrogen group, 
because these elements all exhibit the same valence and many 
parallel compounds. 

More than this, it is found that the members of this group disclose the 
same mutual relationship in their respective atomic weights as the members 
of the group of dyad salt-formers, the group of monad salt formers, and cer- 
tain other natural groups of elements. 

723. The nitrogen group (which is also sometimes called the "antimony 
group") is as follows : 

Elements. Atomic Weight. 

Nitrogen, 14. 

Phosphorus, 31. 

Vanadium, 51. 

Arsenic, 75. 

Antimony, 120. 

Bismuth, 209. 

All are preferably triads and pentads ; but the closest relationship exists 
between phosphorus arsenic and antimony, which from a sub group corre- 
sponding to the sulphur group (sulphur, selenium and tellurium) and -the 
chlorine group (chlorine, bromine and iodine). The atomic weight of arsenic 
is very nearly one-half of the sum of the atomic weights of phosphorus and 
antimony. 

724. Phosphorus is widely and generally distributed throughout the 
material world, but only in small quantities. The waxy or ordinary phos- 
phorus has an extra-ordinary affinity for oxygen, with which it unites even at 
common temperatures, igniting when exposed to the air, and burning vio- 
lently. It also burns in chlorine and bromine. [Red or amorphous phos- 
phorus, however, is comparatively indifferent as to combining energy.] The 
acid-radicals of phosphorus are the most important; but it may also form basic 
compound radicals. 

725. Arsenic and antimony stand in their relations to nitrogen and phos- 
phorus, as selenium and tellurium to oxygen and sulphur. But arsenic, anti- 
mony and bismuth have marked metallic properties, and bismuth has a num- 
ber of salts in which it acts as a positive radical, while arsenic and antimony 
have not. 

726. The gradual changes of the members of the nitrogen group from 
nitrogen to bismuth are interesting. To show their similarities and divergen- 
cies, the following table will suffice: 







CHEMISTRY. 






N. 


P. 


As. 


Sb. 


Bi. 


NH 3 


PH 3 


AsH 3 


SbH 3 




NC1 3 


PCI3 
PCU 


AsCl 3 


SbCl 3 

SbCl 5 


BiCl 3 


N 2 3 


p 2 o 3 


As 2 3 


Sb 2 S 3 


Bi 2 3 


N 2 5 


p 2 o 5 


As 2 O s 


Sb 2 S 5 


Bi 2 5 


NH 4 Br 


PH 4 Br 








HNO3 


HPO3 
H3PO3 


H 3 Asb 3 


HSb0 3 


HBi0 3 




H3PO4 


H 3 As0 4 


HsSbO* 









As 2 S 3 

As 2 05 


Sb 2 S3 

Sb 2 S 5 


Bi 2 S 3 



187 



Vanadium is a rare metal. 

727. Phosphorus (P; at. w. 31) is a soft, waxy, semi- 
translucent, nearly colorless or slightly yellowish solid, of 
peculiar odor and taste. It is of crystalline structure, luminous 
in the dark, poisonous. It melts at 44. ° C, and boils at 290/ C. 
Insoluble in water and sparingly soluble in alcohol; but soluble 
in chloroform and carbon disulphide; in fixed oil it is.solubleto 
the extent of 1 per cent. 

It has such strong affinity for oxygen that if allowed to come 
in contact with air it ignites and burns fiercely, forming phos- 
phorus pentoxide, which is a snowy white solid and which forms 
phosphoric acid when brought in contact with water. Phos- 
phorus must, therefore, be. kept under water, and be handled 
with great caution. 

Phosphorus occurs combined with calcium through oxygen 
in the calcium phosphate of bones. 

728. Preparation. — The normal, ordinary, or yellow phos- 
phorus is made from calcined bone, which is heated with 
charcoal in retorts, the P 4 distilling over: 3Ca(P0 3 ) 2 +5C 2 =P 4 -i- 
Ca 3 (P0 4 ) 2 +ioCO. 

729. Red phosphorus is formed when the ordinary phos- 
phorus is heated to 300 C, excluded from the air, as in C0 2 . 

It is called amorphous phosphorus, does not oxidize in the 
air, is not luminous in the dark, is insoluble in carbon disulphide, 
is infusible and non-poisonous. 

730. P forms two oxides: trioxide, P 2 3 , and pentoxide, 
P 2 5 . The acids of P are: 



165 CHEMISTRY. 

Hypophosphorous acid=H 3 P0 2 . 

Phosphorous acid=H 3 PG 3 . 

Phosphoric acid=H 3 PO i . 

Metaphosphoric acid=HP0 3 . 

Pyrophosphoric acid=H 4 P 2 7 . 

Their salts are called hypophosphites (918), phosphites, 
orthophosphates (914), metaphosphates (916), and pyrophos- 
phates (917). 

731. Phosphoric Acid. — The ordinary phosphoric acid, 
H 3 P0 4 , is orthophosphoric acid, and the Pharmacopoeia con- 
tains a 50 per cent, solution called " Phosphoric Acid," and a 10 
per cent, solution called "Diluted Phosphoric Acid." 

It is most frequently prepared by oxidizing phosphorus by 
means of nitric acid. The phosphorus is placed in nitric acid 
of suitable strength; when the reaction is completed the prod- 
uct is freed from arsenic (derived from the usually impure phos- 
phorus), and from other impurities, and diluted to the required 
strength. 

The reaction is: P 4 +4HN0 3 + 2H 2 0==4H 3 P0 3 +2N 2 2 ; and 
finally 3H 3 P0 3 +2HN0 3 =3H 3 P0 4 +N 2 2 h-H 2 0. 

732. Phosphine, PH 3 , or " phosphoretted hydrogen," or 
hydrogen phosphide, is made by heating P 4 in a solution of 
KOH or NaOH. It is an inflammable, poisonous gas, of a dis- 
agreeable garlicky odor. 

733. Arsenic (As; at. w. 75) is a dark steel-gray crystal- 
line, heavy solid of a dull metallic lustre. It is volatile, distill- 
ing without first melting, the vapors having a yellowish brown 
color and garlicky odor. But in the solid state arsenic is odor- 
less and tasteless. Insoluble in all neutral solvents. 

It occurs mostly in combination with S. Compounds of As 
are white, yellow or red. They are made from the metal or its 
oxide. 

734. Arsenic has two oxides, namely a trioxide or arsenous 
anhydride, As 2 3 , and a pentoxide, or arsenic anhydride, As 2 5 . 

The ordinary " white arsenic," which the Pharmacopoeia 
calls " arsenious acid," is arsenous oxide. As is well known, it 
is poisonous. 



CHEMISTRY. 1 89 

735. With H arsenic forms a gaseous compound called 
" arseniuretted hydrogen; " it is hydrogen arsenide, or H 3 As, 
and is also called arsine. Hydrogen arsenide has a garlicky 
odor, and is very poisonous. 

736. Sulphides and chlorides of arsenic also exist, and an 
iodide of arsenic is contained in the Pharmacopoeia. Among 
the official preparations of As are solutions of potassium arsen- 
ite, sodium arsenate and arsenous acid; the solution of sodium 
arsenate is made of i part of the anhydrous salt to 99 parts of 
water, and the others of one per cent, arsenous anhydride. 

737. Antimony (Sb; at. w. 120) is a heavy, bluish -white, 
crystalline solid of decidedly metallic lustre. Melts at 425 C, 
and vaporizes at white heat. It occurs as " black sulphide of 
antimony," or antimonous sulphide, Sb 2 S 3 . 

Nitric acid does not dissolve antimony but oxidizes it, the 
oxide of antimony thus formed being insoluble in nitric acid. 

Compounds of antimony are white, black, yellow or red. 
They are prepared from the sulphide or the oxide. 

738. The oxides of antimony correspond to those of arsenic. 
The pharmacopceial oxide of antimony is the antimonous oxide 
Sb 2 3 , which is a white powder, insoluble in water. Antimonic 
anhydride is Sb 2 5 . There is also an antimonate of antimonyl, 
SbOSb0 3 . 

739. With S, antimony forms antimonous sulphide, which 
is black when in crystalline form, or orange red when precipi- 
tated ; and antimonic sulphide, Sb 2 S 5 , which is also orange red 
Sulphur salts of antimony exist, as, for example, the sulphanti- 
monate of sodium, Na 3 SbS 4 , and sulphantimonite of sodium, 
Na 3 SbS 3 . 

740. With CI antimony forms SbCl 3 and SbCl 5 . The tri- 
chloride is official in some pharmacopoeias in the form of a 
solution ; that "solution of chloride of antimony " must neces- 
sarily contain a considerable quantity of hydrochloric acid, for 
the SbCl 3 is not soluble in water but instead decomposed by 
it, while it is soluble in a mixture of water and HC1. 



190 CHEMISTRY. 

741. Potassium-antimonyl tartrate (KSbOC^HiOg) is com- 
monly called tartar emetic, and its official title is " tartrate of 
antimony and potassium." It is the only water-soluble anti- 
mony preparation in the pharmacopoeias. 

742. Bismuth (Bi: at. w. 208.9) is a heavy crystalline solid 
of reddish-white color ; melts at 267" C, and vaporizes at white 
heat. It occurs in nature uncombined. Nitric acid dissolves 
bismuth to form the normal nitrate, Bi(N0 3 ) 3 , which is soluble 
in a mixture of nitric acid and water, but decomposed by water 
alone. 

The compounds of bismuth are white, black, red or colorless. 
They are made from the metal. 

743. The oxides of Bismuth are Bi. 2 3 and Bi 2 5 . Chlorides 
and sulphides also exist. 

The normal bismuth nitrate, Bi(X0 3 ) 3 being soluble in glyc- 
erin, is sometimes used as the material out of which other 
bismuth compounds are made. " Citrate of bismuth and 
ammonium " is the only water-soluble preparation of bismuth 
known to pharmacy. 

The so-called ''subnitrate of bismuth" and " subcarbonate 
of bismuth " of the Pharmacopoeia are not bismuth salts but 
bismuthyl salts (BiON0 3 and (BiO) 2 C0 3 ). When a solution 
of normal bismuth nitrate in water and nitric acid is poured into 
water, the salt is decomposed and bismuthyl nitrate produced. 

744. Boron (B; at. w. 11) is an altogether unique element. 
It is, in the free state, a solid. Its most familiar compounds 
are borax and boric acid (formerly called " boracic acid"). 

Borax is sodium pyroborate, Xa 2 B 4 7 . ioH,0: boric acid 
is H 3 B0 3 . 

Although B is a trivalent element, it possesses some analo- 
gies to silicon. 



CHEMISTRY. 191 

CHAPTER XXXV. 

THE CARBON GROUP. 

745. This group embraces carbon, silicon, titanium and tin, 
all of which are quadrivalent. 

746. Carbon (C; at. w. 12) occurs in nature in the free state 
as diamond, graphite and coal. It exists only as a solid, and 
can be neither fused nor vaporized. 

Diamond is the hardest substance known, and possesses 
unsurpassed lustre and brilliancy. It crystallizes in various 
forms of the Regular System. 

Graphite is the so-called " plumbago," or the "black lead" 
of lead pencils, stove polish, etc. 

Coal — hard and soft — consists mainly of carbon, and charcoal 
is also carbon; soot, lamp-black, "bone-black" and coke are 
also different forms of more or less impure carbon. 

The specific weight varies according to the form, or allotropic 
modication as distinctly different forms of any one element are 
called. 

Carbon is one of the most commonly occurring and abundant 
of the elements. It is the most important element in organic 
chemistry. 

747. At common temperatures carbon exhibits no chemical 
affinity whatever for other substances. At a very high heat it 
readily unites with oxygen, forming two different oxides, one of 
which is an acid-forming oxide, C0 2 ; carbonic acid is, however, a 
very weak acid. But its lower oxide, CO, figures as a most 
important compound radical, called carbonyl, and may also be 
said to form carbonic acid by uniting with (HO) 3 . 

Carbon combines with hydrogen in numerous compounds, 
and forms with that element many compound radicals. 

Its compounds with sulphur are analogous to those it forms 
with oxygen. Carbon disulphide, CS 2 , is an ill-smelling liquid. 

It also combines with the halogens. 

With nitrogen it forms the important radical cyanogen which 
lias already been referred to (719). 



192 CHEMISTRY. 

748. Carbon has apparently a variable valence as indicated 
by its oxides CO and C0 2 . But its other compounds show- 
that its ruling valence is that of a tetrad. The most striking 
function of carbon is its passive agency in the formation of com- 
pound radicals. In this respect it occupies among the artiads a 
position analogous to that of nitrogen among the perissads. 

749. Organic Chemistry is defined sometimes as " the chem- 
istry of the carbon compounds." It is also defined as "the 
chemistry of the hydrocarbons and their derivatives." 

If the molecular formulas of inorganic compounds be placed beside the 
molecular formulas of organic compounds, and the two series compared, the 
organic molecules seem very complex and the inorganic molecules compara- 
tively simple. The differences in structure are, indeed, in numerous cases so 
great that the student might easily draw the erroneous conclusion that organic 
chemistry must be governed by laws wholly different from the laws of inor- 
ganic chemistry. But the chemistry of the rose and ruby, the air and the bird, 
gold and the apple, calomel and quinine, stone and bread, must be subject to 
the same laws. Inorganic chemistry and organic chemistry are not merely 
near relatives, of whom we might know one intimately, while having barely a 
speaking acquaintance .vith the other ; they are not as two persons, but as the 
different parts of one man. 

750. The apparent complexity of organic chemistry is the 
natural result of the high valence of carbon, the power of the 
carbon atoms to combine with each other, the stability of the 
carbon bonds, the ability of carbon to combine with other ele- 
ments of the most dissimilar nature, the behavior of carbon 
toward hydrogen and oxygen with which it forms many com- 
pound radicals, etc. 

751. The position of carbon in the first series of elements arranged 
according to their atomic weights (664) is not only the central position, but 
the elements on both sides of it are the first members of important natural 
groups, thus : 

I II III IV III II I 

Li (;), Be (9), B(n), C(i2), N (14), O (16), F (19). 

The valence of these elements, beginning with lithium, increases regularly 
from one to four (C), and then decreases as regularly toward the other end of 
the series. 

752. Carbon, being quadrivalent, has four bonds. Each of its four 
valence units mav be satisfied bv a different radical. 



CHEMISTRY. 1 93 

Carbon atoms may combine with each other in three possible different 

ways, as follows : 

II II 

— C— C — , C=C, or — C — C — 

II II 

Thus two carbon atoms united to each other may present together either 

two, four or six free bonds. A greater number of carbon atoms must produce 

still greater variety. 

753. Other polyvalent elements may, in a similar manner, though not to 
the same extent, be capable of forming different chains, etc. (831}, and as both 
nitrogen, oxygen and sulphur combine with carbon, directly and indirectly, 
the possible combinations would appear to be without limit. Two nitrogen 
atoms may give us — N=N — or =N — N=, and three nitrogen atoms 
=N — N — N=, or — N=N — N=, etc. But oxygen atoms combining with each 
other can only form simple chains with two free bonds, and sulphur atoms 
likewise. 

754. Add to these possible combinations the further fact that not only 
univalent atoms, as those of hydrogen or of chlorine, may unite with the free 
bonds presented by the chains or clusters of carbon atoms, but that compound 
radicals may be united to these free bonds, and, finally, polyvalent radicals, 
elemental or compound, may link the carbon chain or cluster to still other 
radicals, as, for example, in : 

CHo CHo 

I I 

HC O CH 

\ / 

O 

\ / 
HC 

CH 8 

Paraldehyde . 

755. The Oxides of Carbon. — When carbon undergoes com- 
bustion in a limited supply of 2 or of air, the product of the 
reaction is CO, or carbon monoxide, or carbonous oxide. This 
is a colorless, odorless, tasteless gas, which burns with a blue 
flame to C0 2 . Carbon monoxide is poisonous when inhaled. 

The higher oxide is formed carbon is burned in a free sup- 
ply of 2 , and is easily produced by the decomposition of carbon- 
ates by the stronger acids, because carbonic acid, H 2 C0 3 , at 
once splits up into CO2 and H.,0. Carbon dioxide is also called 



194 CHEMISTRY, 

carbonic oxide and " carbonic acid gas." It is colorless, slightly 
pungent, of a refreshing, faintly acidulous taste, soluble in 
water. At ordinary temperatures and pressure it dissolves in an 
equal volume of water; but with the aid of cold and strong 
pressure much larger quantities of C0 2 can be forced into a 
state of solution in water, and such a solution is called " carbonic 
acid water." When inhaled the C0 2 acts as a poison, and a 
comparative small proportion of C0 2 in the atmosphere of a 
room is sufficient to render it unhealthy. 

756. Silicon (Si; at. w. 28.3), which is so abundant in the 
silicates of the earth's crust, as in quartz rock and sand, is analo- 
gous to carbon in the structure of its compounds. It is of the 
greatest importance in its geological relations. 

Glass is composed of silicates of sodium, potassium, calcium 
and lead; glass containing the silicates of K and Ca is hard and 
not easily fused, while flint glass made of the silicates of K and 
Pb is more readily fusible and brilliant, and soft glass made of 
the silicates of Na and Ca fuses very readily. 

757. Tin (Sn; at. w. 119) is also industrially important, 
although not very abundant. Notwithstanding its decidedly 
metallic physical properties it presents many points of resem- 
blance to carbon in its chemical compounds. It is a silver-white 
metal, soft, ductile, of crystalline structure, melting point 
228°C, vaporizable at white heat. It does not oxidize on 
exposure to air, and is, therefore, used to coat iron ware. Tin 
also enters into several very useful alloys. 

This metal occurs in nature as stannic oxide, called " tin- 
stone," or'" tin ore." Compounds of tin are mostly white or 
colorless, and are made from the metal or its chloride. 

758. "Tin salt" is chloride of tin, SnCl 2 , and is used as a 
mordant in dyeing. It is soluble in water containing hydro- 
cloric acid. 

759. Titanium is also chemically a relative of carbon, but it 
is so rare an element that it will not be described here. 

760. The carbon group and the nitrogen group, side by 
side, show some interesting parallels: 



CHEMISTRY. 



*95 



Negative Tetrad; 



Negative Polyvalent Perissads. 



Carbon . . 

Silicon 

Titanium. 



Tin 



Atomic Weight. \ Atomic Weight. 

12 14 Nitrogen 

28.3 j 31 Phosphorus 

48 51 ■ Vanadium 

75 Arsenic 

120 Antimony 

205 Bismuth 



CHAPTER XXXVI. 



SUMMARY. 

761. The electro- negative monads and dyads are salt- 
formers. They are active agents in producing compound 
radicals, which they do by saturating only a portion of the 
valence units of the trivalent and quadrivalent electro-negative 
elements. 

Oxygen and hydrogen are of the greatest importance in the 
relations between other elements and their most numerous com- 
pounds. While these two elements are the principal active 
agents in forming compound radicals, they are opposite to each 
other, in this respect: Oxygen characterizes the negative com- 
pound radicals, while hydrogen characterizes the positive com- 
pound radicals. 

The electro-negative, trivalent and quadrivalent elements are 
not salt-formers; they are passive agents in the formation of 
compound radicals, and act as links, centers, and skeletons, 
by which radicals are united into molecules. 



196 CHEMISTRY. 

CHAPTER XXXVII. 

THE LIGHT METALS. 

762. The uniformly electro-positive elements are all metals. 
These have been classified in various ways. 

Thus they have been divided into two groups: light metals y 
whose specific weights are less than 5, and lower than the specific 
weights of their oxides; and heavy metals, whose specific weights 
are over 5, and higher than the specific weights of their oxides. 

They have also been classified into: alkali metals; alkaline 
earth metals; earth metals, proper; etc. 

The several methods of classification adopted by different chemists must 
necessarily coincide in many places as they are all based upon natural rela- 
tionships. 

763. We may first place the five strongest electro-positive 
metallic radicals together, in the order of their atomic weights: 

Atomic Weights. 

Lithium 7. 

Sodium 23. 

Potassium 39. 

Rubidium 85.2 

Caesium 132.7 

All these metals are monads. It will be observed that the 
atomic weight of sodium is exactly one-half of the sum of the 
atomic weights of lithium and potassium, and that of rubidium 
is almost exactly one-half of the sum of the atomic weights of 
potassium and caesium, a pretty regular gradation is apparent 
in the atomic weights of the whole group, and these five metals 
are the strongest electro-positive radicals known, from caesium 
to lithium, in just the order in which their atomic weights place 
them; caesium being the strongest alkali metal, and lithium the 
least pronounced alkali metal. 

764. As this group includes all of the alkali metals, the 
table becomes all the more significant. Still greater emphasis 
will be given to this exhibit if we place opposite the alkali metals 
all dyad metals having nearly coincident atomic weights: 



CHEMISTRY. 



I 97 



Dyads. 



Atomic Weights. 

Glucinum g. 

Magnesium 24. 

Calcium 40. 

Strontium 87.3 

Barium 137. 



Monads. 



Atomic Weights. 

7 Lithium 

23 Sodium 

30- Potassium 

85-2 Rubidium 

132.7 Caesium 



These five dyad metals stand next after the alkali metals 
in the electro-chemical series in precisely the order in which 
they stand in the preceding table, beginning with barium and 
ending with glucinum. 

All of the ten metals included in the table are light metals, and all the 
" light metals" (762) are included except Aluminum (with the atomic weight 
27) and the rare metals Yttrium (At. wt. 89), Zirconium (At. wt. 90.4), Lanth- 
anum (At. wt. 138), Cerium (At. wt. 140), Didymium(At. wt. 142 now split up 
into two elements), Erbium (At. wt. 166) and Thorium (At. wt. 232), which are 
not so well known. 

765. The alkali metals, then, are all monads, and have 
low specific weights; their hydrates, or compounds with HO, 
are the true alkalies, which are very readily water soluble (with 
the exception of lithium hydrate which is not readily soluble); 
their normal carbonates and phosphates are also freely water 
soluble (except those of lithium, which are rather sparingly 
soluble). Their carbonates and hydrates are not decomposed 
by heat. Their normal salts have either an alkaline or a neutral 
reaction on test paper. 

766. The alkali metals have such intense chemical affinity 
for oxygen that they must be kept immersed in naphtha. They 
even decompose water, appropriating the oxygen so that the 
hydrogen is liberated. Caesium decomposes water with great 
violence; lithium more quietly. These metals also have an 
intense affinity for the halogens and sulphur. Observe that the 
alkali metals decompose water by taking to themselves its oxy- 
gen, while chlorine decomposes water by uniting with the 
chlorine. 



I98 CHEMISTRY. 

Potassium oxide is K 2 0. It reacts with water so violently 
that flame results. The oxides of the alkali metals form 
hydrates when they come in contact with water. 

767. Potassium (K; at. w. 39) exists in nature only in 
compounds. In minerals as silicate; in the salt deposits at 
Stassfurth, Germany, it is contained in the form of chloride; 
and the ashes of plants contain potassium carbonate. The 
juice of grapes contains acid tartrate of potassium, which 
deposits on the bottom and sides of wine vats and casks in the 
form called argots or crude tartar, which, when freed from color- 
ing matter and other impurities, furnishes cream of tartar, 

768. Potassium is a soft bluish white metal which oxidizes 
rapidly when exposed to the air, and decomposes water, from 
which it appropriates the oxygen. It is produced by strongly 
heating K 2 C0 3 with C 2 , the reduced metal being distilled over. 
To protect the metallic potassium from oxidation it is kept in 
some liquid hydrocarbon, as in petroleum. 

769. The potassium compounds are, as a rule, colorless or 
white. They are either alkaline or salty to the taste. They are 
frequently anhydrous, generally water-soluble, and the hydrate, 
carbonate and acetate are deliquescent. Of the common potas- 
sium compounds of the drug store the least soluble are the acid 
tartrate or cream of tartar, the sulphate, chlorate, and perman- 
ganate. 

770. The materials employed for making potassium prepa- 
rations are first the crude chloride from Stassfurth, then the 
carbonate made from that chloride, and the bicarbonate. The 
pharmacopoeias prefer the bicarbonate as the material from 
which to prepare the other potassium compounds, because the 
bicarbonate is crystallized and generally sufficiently pure as 
well as cheap. 

The most common potassium compounds are the hydrate, 
carbonate, bicarbonate, bromide, iodide, nitrate, chlorate, per- 
manganate, acetate, citrate, tartrate and bitartrate, all of which 
are described in the Pharmacopoeia. A solution of potassium 
hydrate, called " liquor potassse " is also official. 



CHEMISTRY. 1 99 

Potassium hydrate, KOH ("potassa '*'),- is extremely caustic 
and corrosive, and, therefore, poisonous. Even the carbonate 
("potash," or " pearl-ash," or " salt of tartar") is destructive 
and poisonous when introduced into the body without sufficient 
previous dilution or in too large quantities. The best antidotes 
are vinegar, lemon juice, citric acid, olive oil, cotton seed oil, 
milk, etc. 

" Saltpetre " is potassium nitrate. 

771. Sodium (Na; at. w. 23) occurs most commonly as 
chloride of sodium, which constitutes " salt." From this the 
carbonate ("sal sodae ") is manufactured on a large scale. 

It is a soft, silver-white metal which, like potassium, must 
be kept in hydrocarbons to keep it from oxidizing, and it is pro- 
duced from sodium carbonate by a process analogous to that by 
which K 2 is made. 

772. Compounds of sodium are, as a rule, white or color- 
less, and water-soluble. Their taste is either alkaline or purely 
salty, or bitterish. Water of crystallization occurs more com- 
monly in sodium salts than in the salts of potassium, and many 
of the crystallized sodium salts effloresce when exposed. 

773- Sodium preparations are made from the carbonate 
which is both cheap and generally sufficiently pure, being crys- 
tallized. 

The most commonly used sodium compounds are the hydrate, 
carbonate, bicarbonate, chloride, bromide, nitrate, sulphate, phos- 
phate, acetate, salicylate, and the tartrate of potassium and 
sodium. There is also an official solution of the hydrate, Na - '- 1. 

Sodium hydrate is called " soda " by the Pharmacopoeia; 
"washing soda" is the crystallized sodium carbonate; and 
*' baking soda" is the bicarbonate. The sulphate is sometimes 
called "Glauber's salt," and the tartrate of potassium and 
sodium is"Rochelle salt." 

774. Lithium (Li; at. w. 7) is a comparatively rare metal, 
and its compounds, therefore, expensive. 

The most compounds are the carbonate, bromide, chloride, 
citrate and salicylate. They are all white, and prepared from 
the carbonate derived from the mineral lepidolite. 



200 CHEMISTRY. 

775. Ammonium is XH,, a positive compound radical 
which forms salts in many respects closely resembling those of 
K, Xa, and Li. It indeed behaves as if it were a compound 
alkali metal. 

Ammonia, or hydrogen nitride, H 3 X, is contained in the gas 
liquor obtained in the manufacture of illuminating gas, and, 
when purified, this ammonia is now the chief material used for 
the production of the ammonium compounds. 

Ammonium compounds are white or colorless, and water- 
soluble. All are odorless except the hydrate and the carbon- 
ate, which have the strong odor of ammonia; all ammonium 
compounds develop the odor of ammonia on the addition of 
potassium hydrate or sodium hydrate. Their taste is alkaline, 
or salty ; sometimes bitterish. 

The most common ammonium compounds are the hydrate, 
carbonate, chloride, bromide, nitrate and acetate. Ammonium 
hydrate is contained in the "water of ammonia'' of the pharma- 
copoeias ; it is sometimes called "caustic ammonia," and also 
u spirit of hartshorn. " The "carbonate of ammonium " of the 
Pharmacopoeia is a complex substance containing carbamate as 
well as carbonate ; this mixed salt is sometimes called "salt of 
hartshorn," and also " sal volatile." Ammonium chloride is 
often called '"'muriate of ammonia," and also "sal ammoniac." 

776. The alkaline earth metals are calcium, strontium 
and barium. 

They are dyads, and have low specific weights. 

Like the alkali metals they have such an intense affinity for 
oxygen that they decompose water. 

Their oxides, however, can be kept and do not react with 
water so violently as do the oxides of the alkali metals. 

Their hydrates are only sparingly soluble in water, and their 
normal carbonates as well as their phosphates are insoluble, while 
their acid carbonates are water-soluble to a small extent. Their 
normal salts, as far as water-soluble, have a neutral reaction on 
test paper. The sulphides are water-soluble. The sulphates 
and oxalates are insoluble. 



CHEMISTRY. 20 1 

By reference to the comparative exhibit on page 197 it will 
be seen that the atomic weight of strontium is very nearly one- 
half of the sum of the atomic weights of calcium and barium. 
Barium is the strongest electro-positive dyad, strontium the 
second; and calcium, the third 

777. Calcium (Ca; at. w. 40) occurs abundantly in the 
form of lime-stone and other calcium compounds. 

The metal is light-yellowish. 

" Chalk " and " marble " are calcium carbonate, and " lime " 
(" quick-lime ") is calcium oxide, while "slaked lime " is cal- 
cium hydrate. 

The most abundant and convenient materials for preparing 
calcium compounds are the carbonate and the chloride. The 
chloride, which is freely soluble in water, is made by saturat- 
ing hydrochloric acid with calcium carbonate, the many insol- 
uble calcium compounds are made by precipitation - from the 
chloride. 

The oxide (" lime ") has the name " calx " in Latin and the 
words calcium and calcination are derived from it. When 
common lime-stone (impure calcium carbonate) is strongly 
heated in the "lime-kiln," it is said to be calci?ied, the carbon- 
ate being decomposed into oxide and C0 2 : 

CaC0 3 =CaO-r-C0 3 . 

When the lime or calcium oxide is put into water, or when 
water is added to the lime, calcium hydrate is formed: 

CaO+H 2 = Ca(OH) 2 . 

The lime water of the drug stores, then, is solution of cal- 
cium hydrate. 

The most common calcium compounds not already named 
are the precipitated calcium carbonate, prepared chalk, dried 
sulphate of calcium, and the phosphate of calcium. 

" Plaster of paris " is the dried sulphate of calcium, which 
when mixed with water unites with it chemically to form a hard 
crystalline solid. 

" Bone-ash " is calcium phosphate from " calcined bones." 



Z02 CHEMIST] 

Preparations of calcium are white or colorless. The insolu- 
ble are tasteless: others have a disagreeable caustic or bitterish 

taste. 

778. Strontium (Sr; at. w. 87.3) is of comparatively little 
importance to pharmacists; and even Barium (Ba; at. w. 157) 
is of minor interest. 

The hydrates of Ca, Sr, and Ba are sparingly soluble in water 
their carbonates, phosphates, sulphates and oxalates insoluble. 

779. The next group, naturally following those of the 
alkali metals and the alkaline earth metals, is the zinc group. 

Glucinum (At. wt. 9) is often classed in this group, but as it is a rare 
metal we shall omit further mention c: it. 
The zinc group, then, consists of: 

Atomic Weight. 

Magnesium 24 

Zinc 65 

C^-mium 112 

It will be seen that in this group, again, the atomic weight 
of the middle member is about one-half of the sum of the atomic 
weights of the other two; but in this case the metal having the 
lowest atomic weight is the strongest positive element and the 
metal having the largest atomic weight is the weakest. But all 
are strongly electro-positive radicals. They are dyads. 

These metals do not exhibit so strong an affinity for oxygen 
as those before considered: they may even be freely exposed to 
the air without becoming oxidized. Their hydrates are not 
water-soluble; but zinc hydrate is soluble in solution of potassi- 
um hydrate or of ammonium hydrate. Their carbonates, phos- 
phates and sulphides are insoluble; but the sulphates, soluble. 

The carbonates of these metals, precipitated from the solu- 
tions of their water-soluble salts by alkali carbonates are not 
normal but basic (containing hydrate as well as carbonate); but 
normal magnesium carbonate can be prepared in other ways. 

780. But we will take up zinc later and treat for the pres- 
ent of magnesium and aluminum, only, because zinc is decid- 
ed".;.- one of the heavy metals. 

The medicinal effects of the compounds of the light metals 



CHEMISTRY. 203 

are alkaline, antacid, laxative and cathartic, except so far only 
as other medicinal properties are imparted to them by the 
negative radicals they contain. They are poisonous only when 
corrosive or chemically destructive. 

In this they differ from the compounds of the heavy metals, 
which, with the exception of the iron compounds, are poisonous, 
and all of which have more decided medicinal properties deter- 
mined by their positive radicals. 

781. Magnesium (Mg; at. w. 24.3) occurs as carbonate 
and silicate, and in spring waters as sulphate and chloride. 
Talcum and asbestos are magnesium silicate with carbonate. 

The principal material used for the production of other 
magnesium compounds is the native carbonate. From this the 
sulphate may be made, and the sulphate is used for the pro- 
duction of purer carbonate and other compounds. 

The metal is silver-white, can be ignited, and burns with a 
most intense light to magnesium oxide. 

782. The compounds of magnesium are white or colorless, 
tasteless when insoluble, bitter when soluble, except the citrate. 
The most commonly used insoluble magnesium compounds 
are the oxide and carbonate; the soluble are the sulphate and 
citrate; chloride is much used in the manufacture of mineral 
waters. 

Magnesium oxide is called (t magnesia " by the Pharma- 
copoeia, and is also frequently called "calcined magnesia," 
because it is made by heating the carbonate. The magnesium 
carbonate of the pharmacopoeias is not the normal carbonate, 
but a compound of carbonate and hydrate. Sulphate of mag- 
nesium is commonly called " Epsom salt," because it is contained 
in the water of the Epsom Springs, England. 

783. Aluminum (Al), a tetrad metal with the atomic 
weight 27, stands alone. 

It is destined to be one of the most important of all metals 
in the near future, for it does not oxidize in air at any tempera- 
ture, and dilute acids have scarcely any effect upon it, except 
hydrochloric acid. 



204 CHEMISTRY. 

Aluminic salts contain two atoms of aluminum tied together 
so that but six of the eight bonds are free to combine with other 
radicals (786). 

The most common salt is "alum." All water-soluble alumi- 
num compounds are astringents. 

Sulphate, chloride, nitrate and acetate are water-soluble ; 
hydrate and phosphate, insoluble ; carbonate does not exist. 



CHAPTER XXXVIII. 

THE HEAVY METALS. 

784. Zinc (Zn; at. w. 65.1) is a bluish-white metal of crys- 
talline structure ; sp. w. 7.2 ; melting point, 412° C; volatilizes at 
about i,ooo° C. It occurs as calamine, which consists of carbonate 
and silicate, and as zinc blende, which is sulphide. 

The metal is obtained by reducing the ore with carbon at a 
high heat. 

785. Zinc compounds are white or colorless, and when 
•soluble they have a disagreeable, bitter, astringent, metallic taste, 
and are poisonous. 

The materials used for the preparation of officinal zinc com- 
pounds are the metal, oxide, carbonate and sulphate. The sul- 
phate is made by dissolving the metal in dilute sulphuric acid, 
the carbonate from the sulphate by precipitation with sodium 
carbonate, the oxide by calcining the carbonate, and the acetate 
as well as other soluble salts by saturating the proper acid with 
the oxide or carbonate. 

786. The Iron Group. — This group is a peculiar one. Its 
members are : 

Atomic Weight. 
Chromium, 52. 

Manganese, 55. 

Iron, 56. 

Nickel, 58.6 

Cobalt, . 5S.6 



CHEMISTRY. 205 

The atomic weights of all, it will be observed, are nearly the 
same. Like aluminum, these metals are pseudo-triads — that is, 
they form series of compounds in which two atoms of the 
metal are tied to each other and act together as one radical with 
six free bonds, thus : 

II II 

-Al— Al— — Fe— Fe— 

II II 

But while aluminum never acts as a dyad or a hexad, the 
metals of the iron group seem to have three separate valences, 
although nickel and cobalt do not exhibit decided evidences of 
sexivalence. 

The metals of the iron group have two principal series of 
compounds — the -ous compounds, in which they act as dyads, 
and the -ic compounds, in which they act as tetrads, two atoms, 
tied together, acting each as a pseudo-triad. 

For convenience, the metals themselves are distinguished by their own 
derived adjectives with the terminations -ous and -ic to specify their 
respective valence. Thus ferrous iron is a bivalent iron atom ; ferric iron is 
two tetrad atoms tied together, and together acting as a pseudo-triad. In the 
same manner we speak of chromous chromium and chromic chromium; man- 
ganous manganese and manganic manganese; nickelous nickel and nickelic 
nickel; cobaltous cobalt and cobaltic cobalt. 

These metals are slowly oxidized in air, and do not exhibit 
great chemical energy ; and their compounds are not as stable 
as those of the metals before described. Their oxides, hydrates, 
phosphates and sulphides are insoluble. Their carbonates are 
so unstable as to begin to decompose rather rapidly as soon as 
they have been formed. Their nitrates, sulphates and haloids 
are readily water-soluble. 

787. Iron (Fe ; at. w. 56) is one of the most common and 
familiar of the metals. The best iron ore is the magnetic oxide 
of iron, or ferroso-ferric oxide. The metal is obtained from the 
ore by reduction with charcoal at high heat. There are three 
distinct forms of commercial iron — steel, cast iron, and wrought 
iron, differing in properties according to the amount of carbon 
they contain. 



206 CHEMISTRY. 

788. There are two classes of iron co m pound s— ferrous 
compounds, which contain ferrous iron (Fe) ; and ferric compounds 
containing ferric iron (Fe 2 ). 

The ferrous compounds are generally green or greenish blue 
when they contain water, white or nearly white when dry. 

The ferric compounds are reddish-brown, or yellowish-red 
when containing water, white or pale yellow when dry. 

But some iron compounds have a lively blue color (as " Prus- 
sian Blue"), others a pure yellow color (as the oxalate), and 
other colors are represented by them. 

Ferrous compounds are produced from metallic iron or from 
ferrous sulphate. Ferric compounds are made from ferric sul- 
phate or chloride, or from ferric hydrate, or by changing the 
ferrous compounds to ferric by means of nitric acid or chlorine. 

As iron dissolves readily in either hydrochloric or sulphuric 
acid, the ferrous chlorides and sulphates are easily made by sat- 
urating these acids with the metal. 

The iron compounds used in medicine are numerous. When 
water-soluble they usually have a peculiar inky or styptic astrin- 
gent taste, except the " scale salts " which are comparatively 
free from the disagreeably inky taste. 

" Green vitriol " is ferrous sulphate. 

"Tincture of Iron " contains ferric chloride. 

789. Lead (Pb ; at. w. 206.4) is also a common metal, com- 
paratively soft, and of great density, melting at 325 C. 

It occurs most commonly as galena, which is lead sulphide. 
The metal is obtained from this ore. 

It is preferably a tetrad, but sometimes also acts as a dyad. 
Besides these variations in its valence it also has the oxide Pb 2 0, 
in which it must be assumed that the two lead atoms are tied 
together. See Silver (797). 

Lead does not oxidize except superficially in the air. It has 
greater affinity for sulphur than for oxygen. The carbonate of 
lead is a basic carbonate similar in composition to the carbonates 
of the metals of the zinc group. 



CHEMISTRY. 207 

Lead compounds are of various colors, some white, others 
colorless, others red, yellow or black. The nitrate and the 
acetate are the only water-soluble lead salts. They are poison- 
ous, and even the insoluble lead compounds are poisonous because 
they slowly yield sufficient quantities of soluble lead compounds 
to produce the poisonous effects. 

The nitrate and acetate serve as materials for the production 
of most of the other lead compounds. 

791. Copper and Mercury. — These two metals are uni- 
formly bivalent in their compounds. Their atomic weights are: 

Atomic V/ eight. 

Copper 63.2 

Mercury 200 

They have been grouped in several different ways with other 
metals (793). 

Notwithstanding their uniform valence, they have two series 
of compounds — the -ous compounds containing mercurous mer- 
cury ( — Hg — Hg — ) or cuprous copper ( — Cu — Cu — ), and the -ic 
compounds formed by mercuric mercury ( — Hg — ) and cupric 
copper ( — Cu — ). 

The metals are not readily oxidized in air without the aid of 
heat. The oxides of copper are stable compounds; those of 
mercury readily decomposed by heat. The hydrates, phosphates 
and sulphides are insoluble. Normal carbonates do not exist; 
the basic carbonates are insoluble. Sulphate, nitrate and 
chloride of cupric copper are water-soluble. Cuprous salts are 
rare and unstable. 

The only water-soluble mercury compounds are the mer- 
curic chloride and mercuric cyanide. Nitrates of mercurous 
and mercuric mercury and mercuric sulphate are decomposed 
by water. 

792. Copper (Cu; at. w. 63.2) is a reddish metal, harder 
than lead, but softer than iron; it does not become tarnished in 
dry air. It occurs in the free state in large quantities. 

The only common copper compounds used in pharmaceu- 
tical work and in medicine is the sulphate, which is a blue, crys- 



208 CHEMISTRY. 

tallized, water-soluble salt, often called blue vitriol. Other cop- 
per compounds are blue, green, brown, or black. All are poi- 
sonous. 

793. Mercury (Hg; at. w. 200) is the only liquid metal. 
It is silver white, and is also called quicksilver. Sp. w. 13.6. 
Boils at 360 C. It occurs in the form of sulphide, or cinnabar. 

All mercury compounds are more or less poisonous, and 
their poisonous character is as usual in the ratio of their solu- 
bility, the mercuric compounds being more dangerous than the 
mercurous. The metal itself, however, does not have a poison- 
ous effect. 

Mercury compounds are white, colorless, red, yellow, or 
black. Only mercuric chloride and mercuric cyanide are water- 
soluble. Mercury nitrates decompose on contact with water. 

794. The materials used for making compounds of mer- 
cury are the metal itself and the mercuric chloride. The solution 
of nitrate of mercury in water containing nitric acid is also 
used. Sulphate of mercury is prepared by heating the metal 
with sulphuric acid, and the sulphate is then used for prepar- 
ing calomel and corrosive sublimate, by double decomposition 
with sodium chloride, the mixture being subjected to sublima- 
tion. 

795. Among the most important preparations of mercury 
are blue mass, blue ointment and mercury with chalk, all of 
which contain finely divided metallic mercury, and the official 
compounds of mercury include the red and yellow oxide, the 
chlorides and iodides, the mercuric sulphate and subsulphate 
and white precipitate. 

"Calomel," or "mild chloride of mercury," is the mercurous 
chloride, Hg 2 Cl 2 . 

" Corrosive sublimate," or" corrosive chloride of mercury," 
is mercuric chloride, HgCl 2 . 

"Red precipitate," or "red oxide of mercury/' is mercuric 
oxide prepared by decomposing the nitrate by heat; it is not a 
precipitate. The "yellow oxide of mercury" is also mercuric 



CHEMISTRY . 2O0 

oxide made by precipitation resulting from double decompo- 
sition between mercuric chloride and potassium hydrate. 

" Green Iodide of mercury " is mercurous iodide; " red iodide 
of mercury" is mercuric iodide. 

"White precipitate" is mercur-ammonium chloride, 
NHgHgCI. 

796. Silver (Ag; at. w. 107.7) * s a beautiful white metal, 
capable of receiving a high polish; soft, ductile, not tarnished in 
pure, dry air. 

It occurs free as well as in the form of sulphide. 

The only silver compound much used is the nitrate which is 
obtained by dissolving the metal in nitric acid, and the product is 
either crystallized or fused and moulded into sticks or pencils. 

Silver nitrate, when cast into cylindrical sticks, is often called 
"lunar caustic." 

Silver oxide is seldom used. It is a dark brown, insoluble 
powder. 

797. Silver is a metal which has been placed by many 
chemists in the same group with potassium, sodium and lithium. 
Others class it with lead and copper. 

By reason of its specific heat and for other reasons it has been recog- 
nized as a monad, and on that account assigned a place beside the alkali 
metals. Its atomic weight is 107.7, which would place it between rubidium 
and caesium. Although silver exhibits but slight affinity for oxygen, it forms 
one of the most powerful bases. Nevertheless, it is a metal of high specific 
weight ; not affected by air, oxygen, or water ; and its compounds do not resemble 
those of the alkali metals to such an extent as to justify its assignment to the 
group of potassium, sodium and lithium. 

Its oxides correspond perfectly with those of lead, and its only readily 
water-soluble salt is the nitrate, while the acetate is slightly soluble ; these 
are the only water-soluble salts of lead, too. 

798. It is interesting to note that the only other perissad metal which has 
some compounds reminding us of the alkali metals is thallium, which also 
exhibits some relationship to lead, has very nearly the same atomic weight as 
lead, and is often placed together with lead in what is then called the lead 
group, containing only these two metals. The properties of thallium and its 
compounds have been described as intermediate between those of lead and the 
alkali metals, and their compounds. The hydrate, carbonate and sulphate of 
thallium are water-soluble. 



2IO 



CHEMISTRY. 



799- Many chemists put gold, silver and the platinum group together ; 
others put silver, copper and mercury together ; others, again, place lead and 
platinum in the same group, gold and thallium in another, and copper and 
mercury in a third group. 

All these facts prove that it is still extremely difficult to effect a classifica- 
tion so natural as to receive general acceptance. 

The following exhibit of the atomic weights of artiad metals with their 
parallel perissads is suggestive : 



ARTIAD5. 



Atomic Weight. 

Palladium 107. 

Platinum 195 . 

Lead 207. 



PERISSADS. 



Atomic Weight. 

108 m . . Silver 

197 Gold 

204 Thallium 



In Mendeleeff's table (664), upon which most of this chapter is based, we 
find copper, silver and mercury together in one column, beside the alkali metals, 
where they naturally fall by reason of their atomic weights, and it is a remark- 
able fact that all of them have corresponding oxides, Ag 3 0, Cu s O and Hg 3 0, 
like those of the alkali metals, K 3 0, Na 3 and Li 3 0. But gold, lead and 
thallium also have analogous oxides, Au s O, Pb 3 and T1 3 0. 

800. Gold appears to be generally a triad, but also some- 
times a monad, having such compounds as AuCl 3 and AuCl, 
Au 2 3 and Au 2 0, etc. Its atomic weight is 196.7. It is one of 
the weakest of the metallic radicals, nearly all its compounds 
being very unstable. The metal itself is not affected by oxy- 
gen, sulphur or acids. The only reagent which will attack and 
dissolve gold is "aqua regia " or some other solution of free 
chlorine. Occurs in nature in the free state only. 

(See also preceding paragraph.) 

801. The Platinum Group. — The metals of this group 
occur in nature only in the free metallic state. They are: 

Atomic Weight. 
Ruthenium 101.4 

Rhodium 103. 

Palladium 106.4 

Osmium I 9°-3 

Iridium *9 2 -5 

Platinum J 94-3 

By their atomic weights, therefore, they fall into two groups, three of 



CHEMISTRY. 211 

them having atomic weights of from 101.4 to 106.4, the others from 190.7 to 
194 3. The specific weights correspond in the same ratio, the first three having 
the sp. w. 12 and the others 21. Relatively the greatest similarity exists 
between: 

Platinum and palladium. 

Iridium and rhodium. 

Ruthenium and osmium. 

Pt and Pd exhibit bivalence and quadri valence; the others also sexi va- 
lence. But the ruling valence of Pt and Pd is 2, and that of Ru and Os, 6; 
while Ir and Rh occupy the middle ground. 

No acids attack any of these metals; they are not directly 
affected by oxygen or sulphur, but free chlorine (in "aqua 
regia ") attacks them. Their alloys, however, dissolve in the 
stronger acids. Soluble double salts are the least unstable com- 
pounds of the platinum metals; all their other compounds are 
extremely unstable. 



CHAPTER XXXIX. 

SUMMARY OF METALS. 



802. The electro-positive elements, or metals, omitting very 
rare elements, may now be reviewed in a general way, with the 
following conclusions: 

The alkali metals possess such energetic affinity for oxygen 
that they oxidize completely and even violently in either air or 
water. The alkaline earth metals do not oxidize in air as rapidly 
as the alkali metals, but still completely; and they decompose 
water, though with less violence than the alkali metals. No 
other metals oxidize perfectly in either air or water, at ordinary 
temperatures, and the direct affinity for oxygen is entirely 
absent in aluminum, silver, gold and the platinum metals. 



212 CHEMISTRY. 

The oxides of alkali metals react with water to form hydrates 
with such energy that they are instantly changed, and with evo- 
lution of great heat, if permitted to come in contact with 
moisture. The oxides of the alkaline earth metals may be kept 
in dry air, but are hydrated by water, though with far less 
rapidity and heat than the alkali oxides. The oxides of other 
metals are not readily or completely hydrated when brought in 
contact with water. 

The hydrates of alkali metals are freely water-soluble, except 
the lithium hydrate. Lithium stands midway between the other 
alkali metals and the alkaline earth metals, the hydrates of 
which are very sparingly water-soluble. 

The oxides and hydrates of all other metals are insoluble in 
water. 

The only normal carbonates are those of the alkali metals, 
thallium and the alkaline earth metals ; but the carbonates of 
potassium and sodium are very freely soluble, those of lithium 
and thallium comparatively sparingly, and those of the alkaline 
earth metals insoluble in water. The carbonates of the metals 
of the zinc group and of lead are basic, and insoluble in water. 
All metallic carbonates, except those of the alkali metals, are 
decomposed by heat. Of many of the heavy metals, no car- 
bonates exist. 

The only water-soluble phosphates are those of potassium, 
sodium and ammonium — the same positive salt radicals which 
have soluble carbonates. 

The only water-soluble metallic sulphides are those of the 
alkali metals and the alkaline earth metals. 

Soluble sulphates are formed by the alkali metals, thallium, 
the zinc, aluminum and iron groups, and copper ; the sulphates 
of the alkaline earth metals and lead are insoluble, and that of 
mercury is decomposed by water. 

All metallic chlorides are water-soluble, except those of silver, 
lead, thallium and mercurous mercury. Chloride of antimony 
is decomposed by water. 



CHEMISTRY. 



213 



The metallic nitrates are all water-soiuble, except those of 
mercury and bismuth, which are decomposed by water. 

The compounds of the alkali metals are the most numerous 
and generally very stable or permanent ; they are also either 
neutral or of alkaline reaction to test paper. The salts of the 
alkaline earth metals are also comparatively stable, and usually 
of neutral reaction; and next in order those of the metals of 
the zinc group. The salts of other metals are less permanent 
and frequently of acid reaction, and the compounds of mer- 
cury, silver, gold and platinum generally unstable and compara- 
tively few. 



CHAPTER XL. 



COMPOUND RADICALS. 



803. Atoms unite with other atoms either singly or in groups. When a 
chlorine atom unites with another chlorine atom to form a molecule of chlorine, 
or with a hydrogen atom to form a molecule of hydrogen chloride, commonly 
called hydrochloric acid, each of these atoms exercises active chemical energy 
or affinity in the creation of the molecule; and when zinc is dissolved in the 
solution of the hydrogen chloride the reaction which sets in produces mole- 
cules of zinc chloride and hydrogen, each chlorine atom passing from the 
molecule of hydrochloric acid to the new molecule of zinc chloride; from this 
molecule of zinc chloride the chlorine atoms can be transferred to still another 
molecule — that of silver chloride — by mixing a solution of the zinc chloride 
with a solution of silver nitrate. At the same time the silver which unites 
with the chlorine to form the silver chloride must part from the group of 
atoms with which it was combined in the silver nitrate and that group unites 
with the zinc which was robbed of its chlorine by the silver. In this last re- 
action, then, we have both single atoms and groups of atoms passing from one 
molecule to another. 

Atoms of different kinds very commonly travel together in certain definite 
groups, the several atoms in such a group being united to each other while 



214 CHEMISTRY. 

some one of the atoms in the group still has one or more unsatisfied valence 
units or free bonds, by which the whole group may thus be united to some 
other atom or group of atoms. 

Thus, all nitrates contain the group N0 3 , consisting of one nitrogen atom 
and three oxygen atoms, and in that group one of the oxygen atoms must 
have one unsatisfied bond or valence unit left, for nitrogen acts here as a pen- 
tad and oxygen is always a dyad, so that three oxygen atoms have six valence 
units together. The group N0 3 is called the nitrate group or the nitrate 
radical, because all nitrates contain this characteristic group; every com- 
pound containing this group is a nitrate, and no compound is a nitrate that 
does not contain it. The nitrate group or nitrate radical united to a hydro- 
gen atom makes nitric acid= HNO a . If we place a piece of silver in the solu- 
tion of nitric acid a reaction ensues, and that product of the reaction which 
remains in the liquid is the salt called silver nitrate = AgN0 3 . The molecule 
of nitric acid, HN0 3 , has, then, become transformed into the new molecule 
AgN0 3 by the exchange of an atom of hydrogen for one of silver; but the 
nitrate group has passed into the new molecule unaltered. Lead put in the solu- 
tion of silver nitrate will take the nitrate radical away from the silver and cause 
the liberated silver atoms to form molecules of silver which separate from the 
liquid in the solid state as a blackish powder. The lead nitrate is Pb(N0 3 ) 2 
because lead is a dyad or has two bonds or valence units, while, as we have 
seen, the nitrate radical has only one, and we must accordingly have two nitrate 
groups to satisfy one atom of lead. Copper placed in the solution of lead 
nitrate usurps the place of the lead producing copper nitrate = Cu(N0 3 ) 2 , while 
lead is precipitated. From the copper nitrate the nitrate radical can in turn 
be transferred to iron nitrate by putting iron in the solution of the copper 
nitrate; the iron nitrate is Fe(N0 3 ) 2 . Now we might mix the solution of 
iron nitrate with a solution of sodium carbonate, which would result in double 
decomposition (529), the products being iron carbonate and sodium nitrate = 
NaNO s . Thus, we have transferred the nitrate radical, N0 3 , from molecule 
to molecule, uniting it successively to several different positive radicals. 

There are many other compound radicals besides N0 3 , and all can be 
transferred from one molecule to another. 

804. Compound radicals are groups of atoms united to 
each other but having one or more unsatisfied valence units or 
free bonds. 

They, therefore, act in the same manner as free atoms, being 
united by their free bonds toother radicals of opposite electro- 
chemical polarity. 

Compound radicals have an invariable valence. 



CHEMISTRY. 215 

805. All oxysalts (900) contain compound radicals. The 
sulphates all contain the characteristic sulphate radical S0 4 ;all 
compounds containing the radical CO s are carbonates ; no com- 
pound can be a phosphate unless it contain the radical P0 4 ; all 
chlorates contain the group C10 3 : and the group CgO^ distin- 
guishes the oxalates. 

806. The compound radicals as well as the elemental radi- 
cals may be divided into two great classes — -positive and negative 
radicals. Compound radicals containing oxygen but no hydro- 
gen are as a rule electro-negative ; those containing hydrogen 
but no oxygen are as a rule electro-positive. But there are 
many negative compound radicals containing both oxygen and 
hydrogen together with carbon, and also many positive radicals 
containing the same elements. 

807. Hydrogen and oxygen together form the very impor- 
tant compound radical HO, or OH, called hydroxyl.. This radi- 
cal combines with itself to form the so-called peroxide of hydro- 
gen = H 2 2 . It unites with many of the metals to form hydrates 
or hydroxides, and with many different negative radicals to form 
acids; with one hydrogen atom and any number of groups of CH 2 
the hydroxyl forms alcohols, and all alcohols contain HO. 

It is, of course, univalent since the hydrogen atom has but 
one bond which ties only one of the two bonds of the oxygen 
atom, leaving one oxygen bond free. 

808. Nomenclature of the compound radicals. They have 
been given names with the termination -yl, as, for instance, 
hydroxyl, carbonyl, carboxyl, nitryl, nitrosyl, sulphuryl, phos- 
phoryl, methyl, ethyl, amyl, glyceryl, phenyl, acetyl, bismuthyl, 
antimonyl, etc. But many compound radicals have names 
which are not in accordance with this system. 



2l6 



CHEMISTRY. 



809. Acid-forming radicals are those which form acids 
when united to the radical hydroxyl, HO. The principal acid- 
forming radicals of inorganic chemistry are : 



Radical. 


Acid Formed. 


CI 
CIO 

cio 2 

CIO3 


HO.C1 
HO.CIO 
HO.CIO, 
HO.C10 3 


Hypochlorous 
Chlorous 
Chloric 
Perchloric 


SO 

so 2 
s 2 o 


(HO) 2 .SO 

(HO) 2 .S0 2 

(HO) 2 .S 2 


Sulphurous 

Sulphuric 

Thiosulphuric 


NO 
N0 2 


HO. NO 
HO.N0 2 


Nitrous 
Nitric 


H 2 PO 
HPO 
PO 

p 2 o 3 
po 2 

HAsO 

AsO 

As 2 3 


HO.H 2 PO 

(HO) 2 .HPO 

(HO) 3 .PO 

(HO),P 2 3 

HO.P0 2 

(HO) 2 HAsO 

(HO) 3 .AsO 

(HO) 4 .As 2 3 


Hypophosphorous 

Phosphorous 

Orthophosphoric 

Pyrophosphoric 

Metaphosphoric 

Arsenous 

Arsenic 

Pyroarsenic 


HSbO 
Sb0 2 


(HO) 2 .HSbO 
HO.SbO, 


Antimonous 
Metantimonic 


B 
B 4 5 


(HO),.B 

(HO),BA 


Boric 
Pyroboric 


CO 
CO 
CN 
SiO 


(HO) 2 CO 
(HO),. (CO), 
HO.CN 
(HO) 2 .SiO 


Carbonic 
Oxalic 
Cyanic 
Silicic 


SnO 


(HO) 2 .SnO 


Stannic 


Cr0 2 
Cr 2 5 
Mn 2 6 


(HO) 2 .Cr0 2 
(HO) 2 .Cr 2 5 

(HO),Mn 2 Q 6 


Chromic 

Dichromic 

Permanganic 



CHEMISTRY. 



217 



810. The principal positive compound radicals of inor- 
ganic chemistry are : 

Ammonium, NH 4 . 

Antimonyl, SbO. 

Bismuthyl, BiO. 

Mercur-amraonium, NH 3 Hg. 

Ammonium is the radical contained in all ammonium salts 
and other ammonium compounds. Antimonyl occurs in the 
so-called " tartrate of antimony and potassium;" bismuthyl, in 
so-called "subnitrate of bismuth;" and mercur-ammonium, in 
so-called " ammoniated mercury." 

811. In organic chemistry the most important compound radi- 
cals of common occurrence or of special interest to pharmacists 
are the following: 



Positive compound radicals: 




NH t 




Ammonium 


CH 3 




Methyl 


CH 2 




Methene 


CH 




Methenyl 


C 2 H 5 




Ethyl 


C 5 H n 




Amyl 


C 6 H 5 




Phenyl 


C 3 H 5 




Glyceryl 


C 2 H 3 




Acetyl (CH3.CO.) 


Negative compound 


radicals: 




HO 




Hydroxyl 


CO 




Carbonyl 


NO 




Nitrosyl 


N0 2 




Nitryl 


CN 




Cyanogen 


CNS 




Sulphocyanogen 



8l2. In paragraph 809 the radicals which form acids with 
the radical HO are enumerated, and the formulas and names of 
the acids are placed opposite the corresponding radicals, respect- 
ively. 

Thus you find that the radical which forms sulphuric acid by 



2lS 



CHEMISTRY 



uniting with hydroxy] HO. is SO.> (sulphuryl), and the formula 
for sulphuric acid is given as (HO)..SOo. This is a very explicit 
formula, showing that sulphuric acid consists of one group 
of atoms represented by SO., and two groups such as are called 
hydroxyl. HO. But for the sake of convenience the formula for 
sulphuric acid is not written as above (HO) 2 S0 2 . but instead it 
is written HgSO*. We will now explain this. 

813. That SOo is a bivalent radical you can readily ascer- 
tain for yourself when you know that in sulphuric acid and all 
other sulphates the sulphur atom is a hexad. There must 
accordinglybe six sulphur bonds and four oxygen bonds in SO- 2 . 
leaving two sulphur bonds free. These are each united to one 
group of hydroxyl. thus: 

O— H 
I 

o=s=o 



O— H 
which may also be more briefly written: 

SOo/OH 
\OH 
or still more briefly : 

S0 8 .(OH) a or (OH)2.S0 8l 
or final! v: 

H 8 S0 4 . 

814. Whenever sulphuric acid forms a sulphate by com- 
bining with any base, it is only the hydrogen of the groups of 
hydroxyl that is exchanged, and one or both of the hydrogen 
atoms may be replaced by another positive radical, as you will 
see clearly by the following formulas: 

H 8 S0 4 Sulphuric Acid. 

KHS0 4 Acid Potassium Sulphate. 

K 5 S0 4 Normal Potassium " 

Na 2 S0 4 Sodium Sulphate. 

CaS0 4 Calcium 






FeS0 4 
.XH,i 2 S0 4 



Ferrous 

Ammonium Sulphate. 



CHEMISTRY. 2IQ 

In other words, when sulphuric acid forms a sulphate with 
any base or metal, the hydrogen of the hydroxyl being replaced,, 
the change would be most correctly represented as follows: 



S0 2 /0— H 


S0 2 /0— K 


\0— H 


NO— K 


Sulphuric Acid. 


Potassium Sulphate. 



But for the sake of convenience, and since the linking oxy- 
gen atoms of the hydroxyl remain in their position, the general 
practice is to write the formula for every acid not by represent- 
ing the radicals of which it is composed, but the replaceable 
hydrogen is separated from and placed in front of the rest of the 
formula. The remainder, after removing the hydrogen, is called 
an acid residue. Thus in H 2 S0 4 the H 2 is all that is replaced by 
another base in the formation of other sulphates, and S0 4 is the 
residue, and, in fact, may well be treated as a radical, because 
the oxygen of the hydroxyl is still united to the S0 2 , which 
makes it SO A . 

815. This is done, then, in writing the formulas of all acids. 
Although all acids contain hydroxyl, only the hydrogen of the 
hydroxyl can be displaced or replaced in the formation of salts, 
and that hydrogen is written first in the formula, the residue 
being placed after it and considered as the characteristic acid 
radical. 

816. Acetic acid is composed of the three radicals, CH 3 , CO 
and OH, and the structural formula (838) for the acetic acid 
molecule is therefore CH 3 .CO.OH, but it is for convenience 
written HC 2 H 3 2 , and sometimes it is written C 2 H 4 2 . To 
write formulas in such a way that the number of replaceable 
hydrogen atoms can at once be seen is a very valuable point, 
however, and, therefore, we should always write the molecule of 
acetic acid as HC 2 H 3 2 . As it has only one hydroxyl group it 
can have only one atom of basic hydrogen which can be replaced 
by any other positive radical ; if the other hydrogen atoms 
or anyone of them should be removed, exchanged or replaced, 
the compound would no longer be an acetate. 



220 CHEMISTRY. 

817. It follows from what has been stated in the preceding 
paragraph that we have for. every acid, inorganic or organic, an 
acid-radical which is shown in its molecular formula, and in the 
molecular formula of every salt (905). You can at once recognize 
any acid or a salt of any particular acid by its radical, if you 
learnwhat that radical is, and if you will learn not only the for- 
mula but also the valence of every such radical, together with 
the formula and valence of every positive radical of common 
occurrence, you will possess the knowledge necessary to con- 
struct the molecular formulas of all the normal compounds 
formed by these radicals respectively. 



CHAPTER LXI. 

TABLES OF RADICALS. 

818, Tables are here given (819 and 820) of all the important 
and commonly occurring simple and compound radicals, positive 
as well as negative, grouped according to their valence, together 
with the generic name of the class of compounds formed by each 
when united to a radical of opposite electro-chemical polarity. 

[In the next chapter we will explain how these tables can be used, and 
how formulas are constructed from the radicals according to their polarity and 
valence.] 

819. Valence of Positive Radicals. 

(Basylous Radicals.) 

Univalent. Compounds formed. 

H Acids 

K Potassium 

Na Sodium 

Li . Lithium 

Ag Argentic 

NH 4 Ammonium 

CH 3 Methyl 

C 2 H 5 Ethyl 



CHEMISTRY. 



[Basylous-Radicals.- 



C5H11 
QH5 

NH 2 Hg 

BiO 

SbO 
Bivalent. 

Ca 

Ba 

Sr 

Mg 

Zn 

Cd 

Pb 

Cu 

Cu 2 

Hg 

Hg 2 

Sn 

Mn 

Fe 

Co 

Ni 
Trivalent. 

Sb 

Bi 

C3H5 
Quadrivalent . 

Sn 

Pt 
Sexivalent. 

Ce 2 

Al 2 



Continued. \ 
Amyl 
Phenyl 

Mercurammonium 
Bismuthyl 
Antimonyl 

Calcium 

Barium 

Strontium 

Magnesium 

Zinc 

Cadmium 

Plumbic 

Cupric 

Cuprous 

Mercuric 

Mercurous 

Stannous 

Manganous 

Ferrous 

Cobaltous 

Nickelous 

Antimonous 
Bismuthous 
Glyceryl 

Stannic 
Platinic 

Cerium 
Aluminic 



222 


CHEMISTRY. 


Mn 2 


Manganic 


Fe 2 


Ferric 


Cr 2 


Chromic 


Ni 2 


Nickelic 


Co 2 


Cobaltic 


820. Valence of 


Negative Radicals. 


(A 


cidulous Radicals.) 


Univalent. 


Forming, 


H 


Hydrides 


CI 


Chlorides 


Br 


Bromides 


I 


Iodides 


Fl 


Fluorides 


Cy or (CN) 


Cyanides 


HO 


Hydroxides (Hydrates) 


CIO 


Hypochlorites 


CvO or (CNO) 


Cyanates 


HS 


Hydrosulphides 


CyS or (CNS) 


Sulphocyanides 


NO" 


Nitrites 


N0 3 


Nitrates 


H 2 P0 2 


Hypophosphites 


CH0 2 


Formiates 


C 2 H 3 2 


Acetates 


C 5 H 9 2 


Valerates 


CigH 31 2 


Palmitates 


Ci S Ho 5 2 


Stearates 


Ci S H 33 Oo 


Oleates 


C 3 H 5 O s 


Lactates 


C,H B S0 4 


Sulphocarbolates 


C 6 H 2 (N0 2 ) 3 


Picrates 


C 7 H 5 O s 


Salicylates 


C 7 H 5 2 


Benzoates 


C 9 H 8 3 


Cinnamates 



Bivalent. 
O 

S 

so 3 

s 2 o 3 
so, 
co 3 

QO, 
HAs0 3 
HSb0 3 
QH 4 0, 
C 4 H 4 5 
QH 4 6 
CrQ 4 
Cr 2 7 
Mn0 4 
Mn 2 O g 
B,0 7 
Trivalent. 

P0 4 
AsO* 

Sb0 4 
B0 3 
C 6 H 5 7 
C 7 HO ? 

Quadrivalent, 

SiO, 

p 2 o 7 

As 2 7 
Sb 2 7 
FeCy 6 
B,0 7 
Sexivalent. 

Fe 2 Cyu$ 



CHEMISTRY. 

[Acidulous-Radicals. — Continued.] 



223 



Oxides 

Sulphides 

Sulphites 

Thiosulphates 

Sulphates 

Carbonates 

Oxalates 

Arsenites 

Antimonites 

Succinates 

Malates 

Tartrates 

Chromates 

Dichromates 

Manganates 

Permanganates 

Pyroborates. 

Phosphates 

Arsenates 

Antimonates 

Borates 

Citrates 

Meconates 

Silicates 

Pyrophosphates 

Pyroarsenates 

Pyroantimonates 

Ferrocyanides 

Pyrobarates 

Ferricyanides, 



224 CHEMISTRY. 

CHAPTER XLII. 

COMPOUND MOLECULES. 

821. We have learnt that all molecules are made up of 
atoms ; that elemental molecules are made up of atoms of but 
one kind; and the compound molecules are made up of two or 
more atoms of two or more different kinds. 

822. Atomicity. — The number of atoms any molecule con- 
tains is expressed by the term atomicity. 

A molecule consisting of but one atom is monatomic, a mole- 
cule containing two atoms (not two kinds of atoms, but two 
atoms, only, whether of the same kind or not) is diatomic, a 
molecule made up of three atoms is triatomic, one of four atoms 
is tetratotnic, and one of five atoms is pejitatomic, and a molecule 
containing six atoms is hexatomic. 

Molecules containing more than two atoms are polyatomic. 

823. The number of atoms which may unite to form one 
molecule is indefinite and subject to extreme differences. 

Most of the elemental molecules are assumed to contain each 
two atoms. There are, however, elemental molecules supposed 
to contain one (mercury, zinc, cadmium and barium), three 
(oxygen as ozone), four (phosphorus and arsenic), and six 
(sulphur under certain conditions) atoms, respectively. 

Of the compound molecules all binary compounds contain 
but two kinds of atoms, and many of them only one of each 
kind. Thus the chlorides, iodides and bromides of all univalent 
(612) metals, and the oxides and sulphides of the bivalent (612) 
metals, contain but two atoms in each molecule. But molecules 
composed of compound radicals may contain a large number of 
atoms. 

A molecule of potassium iodide or calcium oxide contains two atoms; a 
molecule of water, three; ammonia, four; lead nitrate, five; copper sulphate, six; 
sodium sulphate, seven; phosphoric acid, eight; phenolphthalein, thirty-eight; 
olive oil (glyceryl oleate), one hundred and sixty-seven atoms, and the mole- 
cules of many organic compounds contain even a greater number of atoms. 

Inorganic substances have, as a rule, a far more simple molecular struc- 
ture than organic substances, if the present formulas of inorganic chemistry 
are the true ones. 



CHEMISTRY, 



225 



824. Compound molecules are formed in various ways. 

1. By direct union of the component elements, as: 

X+Y=XY. 

This reaction is, however, in most cases less simple than the equation 
indicates. It is really not a mere addition followed by chemical union, for 
the elemental molecules must first be decomposed into their constituent atoms, 
and in many cases the direct union of atoms depends upon a change of val- 
ence in the factors of the reaction under the influence of energetic chemical 
agents, as the elevation of bivalent C to quadrivalent C, or of Civ to Cvi, or of 
Niii to Nv, etc. 

2. Chemical reactions may also consist of apparently simple 
subtraction: 

YXZ— X=YZ+X. 

This is often the result of a reduction of valence of an element under the 
influence of high heat, as the reduction of Svi to Siv, or Nv to Niii. Exam- 
ples of this splitting up of one molecule into several may be found in the 
products of the destructive distillation of organic substances. Heat has a 
tendency to lower the valence of elements. 

But molecules may be divided by the influence of heat without any 
change in the valence of the atoms involved in the reaction, as when CaC0 3 
is split up into CaO and C0 2 , or when phosphate of sodium is converted 
into sodium pyrophosphate, by heat. 

3. Molecules are formed by single selective affinity when substi- 
tution takes place, as when zinc is dissolved in hydrochloric acid — 

Zn 2 +4HCl=2ZnCl 2 +2H 2 , 
or when chlorine is introduced into the molecule of a hydro- 
carbon taking the place of its hydrogen, atom for atom. 

4. Double decomposition is, however, the most frequently 
occurring form of chemical reactions; it is much more common 
than the three other kinds together. In double decomposition the 
products of the reaction generally have the same general struct- 
ure as the factors, and there is simply a mutual interchange of 
radicals brought about by the chemical attraction working simul- 
taneously in two directions but toward the same result. 

825. All molecules, then, are composed of radicals, and all 
chemical reactions take place between radicals. When two 
different molecules are in contact with each other there may be 
a mutual interchange of radicals between them ; or there may be a 



226 CHEMISTRY. 

transfer of a radical from one molecule to another; or new radi- 
cals may be formed by the splitting up of existing compound 
radicals; or by the removal of an atom or group of atoms; or by 
the substitution of one atom or group of atoms *or some other 
atom or group of atoms; or additional radicals may be inserted 
between those already contained in a molecule. 

826. Compound molecules are formed in accordance with 
the valences of the atoms or radicals of which they are consti- 
tuted. 

Equivalent (614) atoms or radicals unite directly in equal 
numbers, or in the ratio of one to one. 

Whenever any two atoms or radicals are united directly to 
each other, each must present the same number of free bonds. 
In other words, when two opposite radicals unite, there must be 
an equal number of bonds on each side. 

827. There can be no molecule with any free bond or bonds. 
Every bond or valence unit presented by the atoms or radicals 
present in the molecule is tied or saturated. 

It follows from the preceding statement that the whole num- 
ber of bonds in any molecule must be even. Again, if there are 
any perissads in the molecule, their number must be even, as 
otherwise the total number of bonds would not be even. 

If there were an odd number of bonds or valence units, not 
all could be paired and there would then of necessity be one or 
more free bonds, which is impossible in a molecule. 

828. Both simple and compound radicals may unite with 
each other directly, or they may be joined together, like links, 
in chains, or groups, or circles. 

It is evident that two equivalent atoms can only form a pair, directly 
united. But one dyad unites with two monads, two dyads with four monads, 
or with one triad and one monad, or with one tetrad; three dyads with six 
monads, or two triads, or with one monad, one dyad and one triad together ; 
etc. When more than two atoms or radicals are contained in one molecule 
they can not all be directly united ; but of three, four, or five radicals, one 
may be in the center of the whole group directly united with each of the 
others (713). 



CHEMISTRY. 



227 



829. Direct union of atoms. — The simplest possible com- 
pound molecules are those formed by two equivalent atoms. 
Two monads, or two dyads, or two triads, or two tetrads 
mutually saturate each other. Thus: 
H and CI, both monads, form 



Kand I 
Ag and Br, 
Ca and O, 
Zn and S, 
B and N, 



dyads, 



triads 



H— CI, or HC1 
K— 1 or KI 
Ag — Br, or AgBr 
Ca=0, or CaO 
Zn=S, or ZnS. 
B=N, or BN. 



830. But when the atoms or radicals are not equivalent the 
molecule is not so simple, for the number of free bonds on each 
side must then be the smallest common multiple of the numbers 
of their respective valence units. 

Thus, if the valence of one radical is 1 and that of the other 3, it follows 
that each radical must present three bonds ; and if one has a valence of 2 and 
the other of 3, each radical must present 6 bonds, or such a number of 
atoms or groups as will have that total number of bonds. 

Thus : 



H 1 

H 1 

H 1 

Cu 11 

Cu 2 IX 

Ca" 

S*v 

C*v 

N rn 

As 111 

A1 2 VI 

K 1 

(BIO)* 

Ba 11 

Fe 11 

Hg 2 " 

Hg" 

Sn'v 

Fe 2 VI 

Sbv 

Pb 11 



and 



O 11 form H 2 


S n 


SoO 


CU 


HCL 


n 


CuO 


On 


Cu 2 


Cli 


CaCl 2 


n 


SOo 


On 


co 2 


n 


N 2 3 


n 


As 2 3 


CI 1 


A1 2 C1 6 


(OH)' 


KOH 


(OH)' 


BiO.OH 


(OH)' 


Ba(OH) 2 


S» 


FeS 


CI 1 


Hg 2 Cl 2 


CI 1 


HgCl a 


CI 1 


SnCl 4 


(FeCy e )'v << 


Fe 4 (FeCy 6 ) 3 


S» 


SboS 5 


(N0 3 )* 


Pb(N0 3 ) 2 



2 25 CHEMISTRY. 

Ca 11 and (OCA) 1 form Ca(OCl) 2 

(NH*) 1 " (S0 4 )« *' (NH 4 ) 2 S0 4 

Fe 2 vi " (S0 4 )« " Fe 2 (S0 4 ) 3 

Ca 11 " (CO3) 11 " CaC0 3 

K* " (CeHaOv) 111 <l K 3 C 6 H 5 7 

etc., etc., etc. 
831. Chains. — Atoms and compound radicals with their so-called bonds 
may be likened to a number of boys with their hands. Any number of boys 
may form a chain by joining their hands together — one hand to the left, the 
other to the right. So can any number of atoms or compound radicals that 
have each two bonds, as: 

—O—O—O— 
There will still be one free bond at each end, just as the end boys in the chain 
would each have one hand free. But suppose you and I join hands, you tak- 
ing my left hand in your right and my right hand in your left; both your 
hands and mine would be tied just as are the bonds of a calcium atom and an 
oxygen atom united into calcium oxide — 

Ca=0. 
But if one boy with two hands and two one-armed fellows form a chain, 
the boy with two hands will have to be in the middle and the others at the 
ends (we do not care much if one turns his back to us as would necessarily be 
the case if both boys had lost their left hands, or both the right hands), and 
there would be no chance of joining in with any more boys at either end, just 
as when two hydrogen atoms, each with but one bond, are united by an 
oxygen atom between them — 

H— O— H. 
A boy with three hands, if we could have one, would act like a nitrogen atom 

\ / 

N 

I 
and could hold three other boys, one with each hand: 

H 

H— N— H 

or, instead of NH 3 , we might have 

H H 

I I 
H— N— C— H 

I 
H 

for carbon has four bonds. 

You can see, then, that all monads which enter into any molecule must be 

at the ends or on the outside (the one-armed boys at the end of the line); that 



CHEMISTRY. 229 

dyads can form a long chain by extending their two bonds in opposite direc- 
tions or they can form a ring; that triads can form the centers of triangles* 
and tetrads the centers of squares, as well as rings, etc. 

832. Linkage. — In any molecule consisting of more than 
two atoms, then, one or more of these atoms, or any group of 
atoms through one of their number, must perform a linking 
function. In other words, the atoms in such molecules are not 
so combined that each and every atom is united directly to every 
other atom, but two univalent atoms may be linked together 
by a bivalent atom as in the water molecule, H — O — H, or in 
potassium hydrate, K — O — H; or, if the molecule consists of at 
least two monads and at least two dyads, a longer chain may be 
formed, as in CI— O — O — O — H; or if tetrads perform the 
linking function there may be branched chain, as in 

H H H H H 

I I I I I 
H— C— C— C— C— C— H ; 

I I I I I 
H H H H H 

in which the hydrogen atoms are linked together by carbon; or 

we may have a triad linking together three monads, as in 

H 

I 
H— N— H; 

or a triad tying together one monad and one dyad, as in 
0=Bi — CI; or a tetrad uniting two dyads as in 0=C=0, or a 
tetrad uniting one monad and one triad as in K — C^N, or three 
or four dyads joined together in a closed chain or ring, as in 

s s 

/ \ / \ 

O—O and in O O; 
\ / 
O 

or such structures as indicated by the following examples may 
result: 

H O O— H 

I I! / 

H— C— C— O— H; 0=P— O— H 

I \ 

H O— H; 



230 CHEMISTRY. 

H O 

H— C— CI; - H— O— C— C— O— H; 

I II 

H O 

H H H 

I I I 

c c c 

/ \ / \ / \ 

H— C C— H H— C C C— H 

in 1 11 1 

H— C C— H; H— C C C— H 

\ / \ / \ / 

C C C 

I I I 

H H H 

833. In all cases of indirect union or linkage, each linking 
atom must present the same total number of bonds as the sev- 
eral atoms linked together by it. 

834. The formulas shown in paragraph 832 are presented only for the 
purpose of illustrating the manner in which the several atoms are held together 
in molecules, and how the valence units or bonds of the several atoms are all 
tied or satisfied, each bond from any one atom being united to one bond from 
some other atom, all the bonds being paired off in this manner. 

But such formulas as these are not generally used because they are too 
unwieldly except for the purpose of portraying the internal structure of mole- 
cules 

835. Molecular formulas are based upon the atomic theory 
(583), the theory of electro-chemical polarity (564), and the 
theory of valence (607); they may also be derived from or veri- 
fied by the hypothesis of Avogadro (599), and the relation of 
specific heat to atomic and molecular weight (589). 

A molecular formula of any compound stands for one mole- 
cule of the compound and for one molecular weight of it 
expressed in hydrogen units, just as any single symbol stands 
for one atom of the element it represents, and for the fixed rel- 
ative weight of that atom as compared with that of hydro- 
gen. 

836. Empirical Formulas are molecular formulas reduced 
to the simplest form of expression showing the kinds of atoms 



CHEMISTRY. 2 3 x 

and the number of each. Thus the empirical formula for 
acetic acid is QH 4 2 . Such formulas are deduced from the 
percentage composition ascertained by ultimate quantitative 
analysis. An empirical formula is correct so far as it goes, but 
does not show the interior arrangement of the atoms or their 
relative positions, except in compounds of .simple radicals. 

837. The molecular formulas of inorganic compounds, as 
commonly written, are nearly always the empirical formulas, 
and they show the structure in many cases because the com- 
pounds of inorganic chemistry are very simple. 

When more than three different kinds of atoms enter into a 
molecule, however, the commonly-used formulas seldom ex- 
press the internal structure. 

The almost universal practice is to write the molecular 
formulas of salts (892), as if they consisted of a metal as the 
positive radical and an acid-residue (814) as the negative rad- 
ical, and this method has been found sufficient as well as con- 
venient. 

838. Rational, Constitutional or Structural Formulas 
are molecular formulas which express the relations existing 
between the several groups of atoms composing the molecule. 
The relations which exist between the several parts of any 
compound may be determined by its reactions or decomposi- 
tions, its syntheses and the valences of the several elements of 
which it is composed. 

Thus, the groups CH 3 , CO and OH are assumed to exist in acetic acid, 
because these groups of atoms can be made to enter or leave the molecule 
unchanged. 

As CO is a bivalent radical, and OH and CH 3 each univalent, the rational 
formula of acetic acid is written CH 3 .CO.OH, and it is assumed to be com- 
posed of methyl (CH 3 ), carbonyl (CO) and hydroxyl (OH). 

Rational, constitutional or structural formulas are valuable, because they 
explain the character and conduct of compounds, in addition to their atomic 
composition, indicating their origin or the substances from which they are 
derived and those into which they may be resolved. 

839. Type Theory. — Some chemists have classified all chemical com- 
pounds into a few groups, each group being referred to some fundamental 
type (Dumas, Laurent and Gerhardt). 



232 



CHEMISTRY 



The proposed types are: 

HC1 ' HoO H S N H 4 C 

Hydrogen Chloride Water Ammonia Methane 

It was assumed that all other compounds are derivatives of one or the 
other, or of more than one of these types, or that the molecular structure of 
any other compound conforms to the general plan of one or more of the four 
fundamental types. 

As developed by Gerhardt the theory of types gradually led to serious 
difficulties, greater importance being attached to the new theory than to the 
atomtic weights. Out of it grew the modified or modern type theory of 
Kekule, and the graphic formulas of Kekule and Frankland. 

The types and their derivatives are illustrated by the following table: 



Water 



Ethyl alcohol 



Ethvl ether 



Acetic acid 



Hydrochloric acid 


H | 

cm- 


Ammonia 


H / 

h[n 

H ) 


Ethyl chloride 


Co H 5 1 
CI \ 


Methylamine 


CH 3 ) 
H [N 

K ) 


Acetyl chloride 


C 2 H s O | 

ci$ 


Dimethylamine 


CH 3 ) 
CH ; -X 
H ) 


Cyanogen chloride 


CN) 

Clf 


Trimethylamine 


CH 3 ) 
CH 3 ^N 
CH 3 ) 








H i 



H | 



2 j^ 5 ^-0 Chlormethane 



£*H* \ O Methyl alcohol 



2 „ ,- O Isopropyl alcohol 



H I 
if 



OH 

H 

H 

H J 
CH 3 ) 
CH 3 ( 
OH f 

H 



V c 



CHEMISTRY. 



*33 



840. The relationship of natural groups of elements is generally dis- 
closed by the molecular formulas of their compounds, and the difference 
between radicals as to their valence may at the same time be illustrated by 
placing several groups of molecular formulas beside each other, thus — 

C1H OH 2 NH 3 CH 4 

BrH SH 2 PH 3 SiH 4 

IH SeH 2 AsH 3 TiCl 4 

FH TeH 2 SbH 3 SnCl 4 

CyH MgCl 2 BiCl 3 

KC1 ZnCl 2 

841. But the relative combining value of an element is not alwavs evi- 
dent from the molecular formulas of its compounds compared with other simi- 
lar formulas. 

In fact it is easy to be led into erroneous ideas in some cases by a super- 
ficial comparison of formulas. 

For instance, the formulas Sb 2 3 , As 2 3 , N 2 3 , Bi 2 3 , C1 2 3 , Fe 2 3 , 
Mn 2 3) Cr 2 3 , A1 2 3 , Ni 2 3 and Co 2 3 might lead us to suppose that each of 
the several elements united to oxygen in these formulas must be trivalent, 
which is not the case. A thorough examination of all the known compounds 
has led to the adoption of some one ruling valence for each element, and the 
apparent inconsistencies can be explained more or less satisfactorily. If the 
formula for ferrous chloride is really FeCl 2 and not Fe 2 Cl 4 , we would naturally 
regard Fe as bivalent and not quadrivalent in that compound; but the Fe in 
Fe 2 Cl 6 is not trivalent but quadrivalent. Graphically the two chlorides of 
iron may be portrayed as follows: 

CI CI 
CI— Fe— CI I I 

and CI— Fe— Fe— CI 
Ferrous chloride 

CI CI 
Ferric chloride 
In mercurous and cuprous compounds the groups Hg 2 and Cu 2 are 
apparently bivalent; but in mercuric and cupric compounds the single atoms 
of Hg and Cu are also bivalent. 

842. Substitution. — Certain atoms or radicals have the power to crowd 
out other atoms or radicals from molecules. Those of equal valence replace 
each other in equal numbers (614). But a bivalent radical may replace two 
monads, etc. The atom or radical thus displaced and replaced may be at the 
end of a chain, or in the middle of it or of a ring or closed chain, or in the 
center of a group, or it may be one of the atoms in a compound radical. 

Chlorine can be introduced into the molecule CH 4 , one or two or three or 
all of the atoms of H being replaced by CI, producing CH 3 C1, CH 2 C1 2 , CHC1 3 
or CC1 4 as the case may be. Chlorine is then said to be substituted for the 
hydrogen. 



234 CHEMISTRY. 

In the same manner guncotton is derived from cotton by substitution, the 
group NOo replacing H. 

843. Derivatives are compounds formed by substitution or replacement 
of one or more atoms or groups of atoms in a molecule, the general struct- 
ure of which remains similar. The terms "derivative" and "substitution 
product" are synonymous. 

Entire series of compounds, differing from each other by some fixed group 
of atoms or by a multiple of that group, are known. The marsh gas series of 
hydrocarbons beginning with CH 4 consists of many members, each differing 
from the next preceding member by CH 2 . Such a series is called a homolo- 
gous series. It can be assumed that these compounds are formed by substitu- 
tion, one atom of H being replaced by one atom of CH 3 , by which CH 4 would 
give rise to C 2 H 6 . the latter to C 3 H 8 , etc. 



CHAPTER XLIII. 

CLASSES OF COMPOUNDS. 



844. Compound molecules consist of two or more kinds of 
atoms. Those that contain but two kinds of atoms are called 
binary compoicnds those that are composed of three kinds of atoms 
are ternary compounds : if four kinds of atoms are united in one 
molecule the compound is called quaternary. But these dis- 
tinctions are of little value as compared with a classification 
based upon the manner in which the atoms are united and the 
chemical behavior of the resulting compounds. 

845. Chemical compounds are commonly classified into 
certain natural groups according to their general structure and 
chemical properties. The principal classes are as follows: 

A. Inorganic Compounds. 
1. Oxides. 
Sulphides. 

Haloids (Chlorides, Bromides, Iodides and Cyanides). 
Bases. 
Acids. 
Salts. 





CHEMISTRY 




i?. Organic Compound 


I. 


Hydrocarbons. 7. Ethers or Oxides. 


2. 


Organic Haloids. 8. Ethereal Salts. 


3- 


Alcohols (and Mercaptans). 9. Carbohydrates. 


4- 


Aldehydes. 10. Glucosides. 


5- 


Ketones. 11. Akaloids. 


6. 


Acids. 



■35 



CHAPTER XLIV. 

OXIDES AND SULPHIDES. 

846. Oxides. Whenever any radical unites with oxygen 
directly the resulting compound is called an oxide. 

All elements except fluorine combine with oxygen, and there 
are accordingly a great number of oxides of both non-metallic 
and metallic elements. There are also oxides formed by com- 
pound radicals. Many of the elements form each more than 
one oxide (579), combining with oxygen in more than one pro- 
portion. Higher oxides contain a greater proportion of oxygen 
than the lower oxides of the same radicals. 

847. Acid-forming oxides are those oxides which have 
the power to form acids with water. They are also called 
anhydrides of the acids. 

Sulphuric oxide, or sulphuric anhydride, is the oxide S0 3 , which, when 
added to water, forms, by chemical reaction, sulphuric acid, H 2 S0 4 . 

Phosphoric anhydride, P 2 Os, forms phosphoric acid with water. 

Nitrogen pentoxide, or nitric anhydride, with water, forms nitric acid. 

The oxides of the non-metallic elements, especially their higher oxides, 
are acid formers or anhydrides. 

Acid-forming oxides can unite directly with basic oxides (848) to form 
salts (892). Thus S0 3 with MgO will form MgS0 4 . 

848. Basic oxides are oxides which have the power to 
form basic hydrates (874) with water, or which combine with 
acids to form salts. The basic oxides or base-forming oxides, 
as a class, do not contain as much oxygen as the acid-forming 
oxides. Oxides of the metals are nearly always basic. 

849. Indifferent or neutral oxides are those oxides which 
form neither acids nor bases. 



236 



CHEMISTRY. 



N 2 0, N 2 2 , N 2 4 , Mn0 2 , Mn 3 4 , Pb0 2 , etc., are examples. 

850. All oxides may be. said to be insoluble in water; they 
either react with water to form acids or bases ; or, if not 
changed chemically by water, they are not dissolved 

851. Preparation of Oxides. — The metallic oxides are 
produced by heating the hydrates or carbonates (919), or by 
oxidizing the metals (802), or by double decomposition between 
the metallic salts and the alkali hydrates (874). 

852. Officinal Oxides. — Water, Chromic Anhydride (called 
"chromic acid"); Arsenous Anhydride (called " arsenous 
acid"); Calcium Oxide (called "lime"); Magnesium Oxide 
(called " magnesia ") ; Zinc Oxide, Mercuric Oxide (red and 
yellow), Silver Oxide and Antimonous Oxide. 

853. Table of Common Oxides, with their Molecular Formulas 
and Molecular Weights: 



Names 


Formulas 


Molecular 
Weights. 


Hydrogen (water) 
Potassium 
Sodium 
Lithium 


H s O 
K 2 
Na 3 
Li 2 


18 

94 
62 

30 


Silver 


A s 2 o 


232 


Mercurous 
Cuprous 


Hg 2 
Cu 2 


416 
143 


Nitrogen Monoxide 


N 2 


44 


Calcium 

Barium 

Strontium 

Magnesium 

Zinc 

Cadmium 


CaO 

BaO 

SrO 

MgO 

ZnO 

CdO 


56 

153 
103 

40.3 
81 
128 


Mercuric 


HgO 


216 



CHEMISTRY. 



237 



Names. 


Formulas 


Molecular 
Weights. 


Cupric 


CuO 


79.2 


Carbon 
Lead 


CO 

PbO 


28 
222.4 


Manganou 
Ferrous 
Cobaltous 
Nickelous 


MnO 
FeO 

CoO 

NiO 


7i 

72 

74.6 

74.6 


Sulphur dioxide 
Carbon dioxide 
Tin dioxide 
Magnanese dioxiae 


SOo 

co 2 

SnOo 
Mn0 2 


64 
44 

87. 


Nitrous Anhydride 
Arsenous Anhydride 
Antimonous 
Bismuthous 
Boron 


N 2 O a 

As 2 O a 

Sb 2 Q 3 

Bi 2 3 

B 2 3 


76. 
198 
288 
466 

70 


Aluminum 

Chromic 

Manganic 

Ferric 

Cobaltic 

Nickelic 


A1 2 G 3 

Cr 2 G 3 

Mn 2 3 

Fe 2 3 

Co 2 3 

Ni 2 G 3 


102 
r 5 2 

160 

165.2 

165.2 


Chromic Anhydrid 


Cr0 3 


100 


Nitrogen 


N 2 0, 


92 


Manganese 

Iron 

Lead 


Mn 3 4 

Fe 3 0, 
Pb s O, 


229 
232 
683. 


Nitrogen v 
Phosphorus 
Arsenic 
Antimonic 


N 2 5 

p 2 o 5 

As 2 O s 

Sb 2 6 


108 
142 
230 
320 



238 CHEMISTRY. 

854. Sulphides. — When any positive radical unites with 
sulphur the compound thus produced is a sulphide. 

Analagous with the acid-forming and base-forming oxides 
are the acid-forming and base-forming sulphides, which have the 
power to unite with each other to form sulphur-salts. 

The sulphides of hydrogen, carbon, arsenic, antimony, and 
the electro-positive radicals generally, are commonly occurring 
compounds. 

855- The only water-soluble sulphides are those of hydrogen, 
the alkali metals, and the alkaline earth metals. 

856. Preparation of Sulphides.— Sulphides are prepared 
in various ways. 

Sulphur does not combine with hydrogen except when both 
are in the nascent state, and hence hydrogen sulphide can only 
be made by decomposing other sulphides with acids. 

Carbon sulphide is produced by slowly heating carbon and 
sulphur together. 

Metallic sulphides are made by strongly heating the metal 
(or its hydrate or carbonate) with sulphur, or by double decom- 
position between metallic salts and hydrogen sulphide or other 
water-soluble sulphides. 

857. Officinal Sulphides. — Hydrogen Sulphide (used as a 
reagent only), Carbon Disulphide (called commonly " bisulphide 
of carbon"), impure Potassium Sulphide (called " sulphurated 
potassa," or "liver of sulphur") Sodium Sulphide, Ammonium 
Sulphide (as a reagent only), impure Calcium Sulphide (called 
" sulphurated lime "), Ferrous Sulphide (as a material for prepar- 
ing hydrogen sulphide), Antimonous Sulphide (as crude "black 
sulphide of antimony "), purified black sulphide, and precipitated 
brownish orange-yellow sulphide (called " sulphurated anti- 
mony "), Antimonic Sulphide, and the very indefinite so-called 
Oxy-sulphuret of Antimony (also called " Kermes Mineral "). 



CHEMISTRY. 



2 39 



858. Table of Common Sulphides with their Molecular Formulas 
and Molecular Weights. 



Names. 


Formulas. 


Molecular 
Weights. 


Hydrogen 
Potassium 
Sodium 
Ammonium 


H 3 S 

K 2 S 

Na 2 S 

(NH 4 ) 2 S 


34 
no 

78 
68 


Silver 


Ag 2 S 


247.4 


Mercurous 
Cuprous 


Hg 2 S 
Cu 2 S 


432 
158.4 


Calcium 


CaS 


72 


Strontium 
Barium 


SrS 
BaS 


1J 9-3 
169. 


Zinc 

Cadmium 

Cobalt 

Nickel 

Manganous 

Ferrous 


ZnS 

CdS 

CoS 

NiS 

MnS 

FeS 


97.2 
144 

9 1 
90.7 

87. 
88 


Mercuric 
Cupric 


HgS 
CuS 


232 

95-4 


Plumbic 


PbS 

FeS 3 


238.9 


Ferric 


120 


Arsenous 

Antimonous 

Bismuthous 


As 2 S 3 
Sb 2 S 3 
Bi 2 S 3 

As 2 S 5 
Sb 2 S, 


246 

33 6 

513.8 


Arsenic 
Antimonic 


310 
400 



240 CHEMISTRY. 

CHAPTER XLV. 

859. Haloids are the compounds formed by metals or posi- 
tive compound radicals with any one of the halogens (696), 
which are fluorine, chlorine, bromine, iodine, cyanogen (and 
ferrocyanogen). 

The haloids are also called " haloid salts," which is tautological. 

Chlorides, bromides, iodides, and cyanides are the principal 
haloids. The haloids of hydrogen are the so-called hydrogen 
acids (888). 

860. Chlorides are formed by direct union of positive radi- 
cals with chlorine. 

Thus we have chlorides of hydrogen and of all the metals, 
and also of positive compound radicals, as of NH i; NH 2 Hg, 
CH 3 , CH 2 , CH, BiO, SbO, etc. 

861. By oxy-chloride is meant a metallic chloride which is in some man- 
ner combined or associated with the oxide or hydrate of the same metal. 
Bismuthyl and antimonyl chlorides are both commonly called oxy-chlorides, 
because they contain oxygen; but they seem to be normal chlorides of com- 
pound radicals. 

862. Chlorides are generally water-soluble; those of silver, 
lead, bismuthyl, antimonyl, and mercurous mercury are familiar 
exceptions. 

863. Many of the chlorides are readily produced by saturat- 
ing hydrochloric acid (hydrogen chloride), with the metals or 
their oxides, hydrates, or carbonates. Other chlorides are 
obtained by the action of free chlorine upon the proper radicals 
or their compounds, or by double decomposition between chlo- 
rides and other compounds. 

Insoluble chlorides are, of course, prepared by precipitation 
(1022). 

864. Officinal Chlorides. — Hydrochloric Acid, and the 
chlorides of Potassium, Sodium (common "salt") Lithium, 
Ammonium, Barium (as a reagent), Calcium, Zinc, Ferrous 
Iron, Ferric Iron (solid as well as in solution and in the tincture); 
Mercurous Mercury (the Mercurous Chloride is commonly called 
u calomel"); Mercuric Mercury (the Mercuric Chloride is com- 



CHEMISTRY 



241 



monly called " corrosive sublimate "); Mercur-Ammonium (the 
Mercur-Ammonium Chloride is commonly called " ammoniated 
mercury," and also "white precipitate "), and Gold (mixed with 
Sodium Chloride). 

865. Table of Common Chlorides with their Molecular Formulas 
and Molecular Weights: 



Names. 


Formulas. 


Molecular 
Weights. 


Hydrogen (Hydrochloric 






Acid) 


HC1 


3 6 -4 


Potassium 


KC1 


74.6 


Sodium 


NaCl 


58.5 


Lithium 


Li CI 


42.5 


Ammonium 


NH,C1 


53-5 


Mercur-ammonium 


NH 2 HgCl 


251.5 


Silver 


AgCl 


143-4 


Gold (Aurous) 


AuCl 


232.7 


Antimonyl 


SbOCl 


I7I-4 


Bismuthyl 


BiOCl 


258.9 


Nitrosyl 


NOC1 


55-4 


Mercurous 


Hg a Cl 2 


470.9 


Cuprous 


Cu 2 Cl 2 


197.7 


Calcium 


CaCU 


no. 9 


Strontium 


SrCU 


158.5 


" with water 


SrCl~.6H 2 


266.6 


Barium 


BaCl 3 


207.9 


" with water 


BaCL.2H 2 


243-9 


Magnesium 


MgCl 3 


95-2 


with water 


MgCk6H 2 


203.3 


Zinc 


ZnCl 3 


136.2 


Cadmium 


CdCh 


182.9 


" with water 


CdCl 2 .2H 2 


218.9 


Mercuric m 


HgCl 


270.9 



242 



CHEMISTRY. 



Names. 


Formulas. 


Molecular 
Weights. 


Cupric 

" with water 


Cu CI. 
CuCh$2H a O 


134-3 
152-3 


Molybdous 

Platinous 

Stannous 

" with water 


Mo'CU 
Pt CU 
Sn CI,. 
Sn C1, 2 H 2 


166.9 
265.9 
189.9 

207.9 


Plumbic 


Pb CI. 


277.9 


Chromous 


CrCl. 


123 


Manganous 

" with water 
Ferrous 

" with water 
Cobaltous 

" with water 
Nickelous 

" with water 


Mn CU 

Mn Cl a4 H 3 

FeCl. 

Fe Cl 24 H a O 

CoCU 

Co CU6H 2 

Ni CU 

Ni C1»6H 2 


125.9 

198 

126.9 

198.9 

129.9 

23* 
129.6 

237.7 


Nitrogen trichloride 

Phosphorus 

Arsenic " (ous) 

Antimony " (ous) 

Bismuth " (ous) 


NC1 3 

PCI3 

AsCl 3 

SbCl 3 

BiCl 3 


120.4 
137.4 
181. 3 
226.3 

3I5.3 


Gold (Auric) 


Au Cl 3 


303-6 


Stannic 
Molybdic 
Platinic 
Uranous 


Sn Cl 4 
Mo CI, 
Pt0 4 

uci, 


260.8 
237.8 

33^ 
381.4 


Phosphorus pentachloride 
Antimonic 


PC1 5 
SbCl 5 


209.3 
297-3 


Tungstic chloride 


WC1 6 


39 6 -7 


Manganic 


Mn 2 Cl 6 

• 


322.7 



CHEMISTRY. 



243 



Names. 


Formulas. 


Molecular 
Weights. 


Ferric 

" with water 
Cobaltic 
Chromic 

" with water 


Fe 2 Cl« 
Fe 2 Cl 6 i2H 2 
Co 2 Cl 6 
Cr 2 Cl« 
Cr 2 Cl 6 i2H 2 

Al 2 Cl 6 
Ce 2 Cl 6 


324.7 
54o.9 
271.7 
316.9 

533 


Aluminum 
Cerium 


266.7 
493 



866. Bromides are the compounds of positive radicals with 
bromine. 

Hydrobromic acid and the bromides of Potassium, Sodium, 
Lithium, Ammonium, Calcium, Magnesium, Zinc and Iron are 
used in medicine and pharmacy. All of these are water-soluble. 
They are prepared in various ways, as by saturating hydrobromic 
acid with oxides, hydrates, or carbonates; by the action of 
bromine upon a metal in the presence of water; by the chem- 
ical solution of bromine in the solution of potassium or sodium 
hydrate, and by double decomposition between bromides and 
other compounds. 

867. Table of Common Bromides with the Molecular Formulas 
and Molecular Weights. 



Names. 


Formulas. 


Molecular 
Weights. 


Hydrogen (Hydrobromic 

Acid) 
Potassium 
Sodium 
Lithium 
Ammonium 

Silver 


HBr 

KBr 
NaBr 
Li Br 
NH,Br 

AgBr 


80.9 

119 
103 

87 
98 

187,9 



244 



CHEMISTRY. 



Names. 


Formulas. 


Molecular 
Weights. 


Calcium 

Magnesium 

Zinc' 

Ferrous 

Ferric 


Ca Br, 
Mg Br 2 
ZnBr 2 

Fe Br 2 

Fe 2 Br 6 


199.9 
184.2 
225.2 

215.9 
59i-7 



868. Iodides are the compounds of positive radicals with 
iodine. 

The iodides which are met with in pharmaceutical work are 
water-soluble with the exception of those of silver, mercury and 
lead; mercurous iodide is quite insoluble in water; mercuric 
iodide is nearly insoluble in cold water and sparingly soluble in 
boiling water; and lead iodide requires about 200 times its 
weight of boiling water to dissolve it. 

869. Preparation of Iodides. — They are prepared from iodine, 
potassium iodide or iodide of iron. 

Hydriodic acid is made by bringing hydrogen sulphide in 
contact with iodine in water, when the sulphur gives up its place 
to the iodine: 2l 2 -t-2H 2 S=4HI + S 2 . Iodides of potassium and 
sodium may be obtained (together with some iodate) by dissolv- 
ing iodine in solutions of the alkali hydrates, or by double 
decomposition from iron iodide. Iodides of sulphur, iron, zinc 
and mercurous mercury can be prepared by direct union of the 
elements. Other methods of preparation of iodides depend 
upon double decomposition between some water-soluble iodide 
and some other compound, as when hydriodic acid is made from 
potassium iodide and tartaric acid: 

KI + H 2 C 4 H i 6 =HI + KHC 4 H,0 6 . 

The insoluble iodides of silver, lead and mercuric mercury 
are made by precipitation (double decomposition), potassium 
iodide being one of the factors of the reaction. 



CHEMISTRY. 



2 45 



The most common methods of making the iodides of potas- 
sium, sodium, ammonium and calcium depend upon double 
decomposition with iodide of iron. 

870. Officinal Iodides. — Hydriodic Acid (in the form of 
Syrup) and the Iodides of Sulphur, Arsenic, Potassium, Sodium 
Lithium, Ammonium, Calcium, Zinc, Ferrous Iron (in the form 
of the solid salt, saccharated iodide, syrup and glycerite), Lead, 
Mercurous Mercury (this iodide being commonly called " green 
iodide of mercury " or " protiodide of mercury ") Mercuric Mer- 
cury (the mercuric iodide being commonly called " red iodide of 
mercury " or " bin-iodide of mercury ") and Silver. 

871. Table of Common Iodides with their Molecular Formula s 
and Molecular Weights: 



Names. 


Formulas. 


Molecular 
Weights. 


Hydrogen 

Potassium 

Sodium 

Lithium 

Ammonium 


HI 

KI 

Nal 

Li 

NHJ 


127.8 

166 

149.9 

?33-9 

144.9 


Silver 


Agl 


234-S 


Bismuthyl 


BiOI 


y^^ 


Mercurous 


Hg 2 I 2 


653-7 


Calcium 

Barium 

Strontium 

Zinc 

Cadmium 


Cal 2 
Bal a 

Srl 2 
Znl, 

cdi; 


293.7 

39°-7 
341-3 
319 
365-7 


Mercuric 


Hgl 2 


453-7 


Plumbic 


Pbl 2 


460.7 


Manganous 


Mnl a 


308.7 



246 



CHEMISTRY. 



Names. 


Formulas. 


Molecular 
Weights. 


Ferrous 


Fel* 


309-7 


Sulphur 


S 2 ^2 


317.8 


Arsenous 


Asl 3 


455-6 


Ferric 


Feje 


873 1 



872. Cyanides are the compounds of positive radicals with 
the compound radical CN y called cyanogen; ferro-cyanides 
with the radical FeCy 6 . 

The only cyanides of pharmaceutical interest are hydrogen 
cyanide or Hydrocyanic Acid (also called " Prussic acid"), 
Potassium Cyanide, Silver Cyanide, Mercuric Cyanide, Ferro- 
cyanide of Potassium (called commonly " yellow prussiate of 
potash "), Ferricyanide of Potassium (as a reagent only), and 
Ferrocyanide of Iron (commonly called " Prussian blue "). 

The cyanides of hydrogen, potassium and mercury are water- 
soluble. 

Hydrocyanic acid is prepared by the decomposition of ferro- 
cyanide of potassium with sulphuric acid, or by decomposing 
silver cyanide with hydrochloric acid. Other cyanides, and the 
ferrocyanides, are also made by double decomposition. 

873. Table of Common Cyanides, Ferrocyanides and Ferricyan- 
ides, with their Molecular Formulas and Molecular Weights: 



JVames. 


Formulas. 


Molecular 
Weights. 


Hydrogen (Hydrocyanic 

acid) 
Potassium 

Silver 

Zinc 


HCN 
KCN 

AgCN 

Zn(CN) 2 


27 
65 

133-9 

1 17. 3 



I 



CHEMISTRY 



Names. 


Formulas. 


Molecular 
Weights. 


Mercuric 

Ferrocyanides. 

Potassium 

Iron 

Ferricyanide. 
Potassium 


Hg(CN) 2 

Kfe(CN).. 3 H 2 
Fe{FeCy 6 ) 3 

K^e(CN) 6 


252 

422.5 
860 

3 2 9 



CHAPTER XLVI. 



BASES. 

874. Bases or Hydrates are the compounds formed by 
positive radicals with the compound radical HO or OH. called 
hydroxyl. Hydrates are also called hydroxides. 

Bases are formed when basic oxides are brought in contact 
with water. Sometimes the metallic oxides react violently with 
water, as the oxides of the alkali metals, and in a less degree the 
oxides of the alkaline earth metals; other metallic oxides react 
with water but slowly; others, again, not at all. 

Bases unite with acids to form salts. 

The hydrates of potassium, sodium and ammonium are called 
alkalies, and these are extremely caustic, corrosive, or destructive 
to organic matter, so that they must be cautiously handled. 

875. The freely water-soluble hydrates are the alkalies. Spar- 
ingly water-soluble are the hydrates of lithium, barium, stron- 
tium and calcium. The other metallic hydrates are insoluble in 
water. 

The water-soluble bases turn certain red vegetable colors blue. 



248 



CHEMISTRY. 



876. The hydrates of potassium and sodium are prepared 
from the carbonates by double decomposition with calcium 
hydrate. Ammonium hydrate is prepared by decomposition of 
ammonium chloride with calcium oxide. The alkali hydrates 
are largely employed in pharmaceutical chemistry as precipi- 
tants in making insoluble hydrates and oxides, etc. 

The hydrates of calcium and barium are made by adding 
water to the oxides. 

Insoluble metallic hydrates are made by precipitation 
(double decomposition). 

877. Officinal hydrates- — Potassium Hydrate (commonly 
called "potassa" and " caustic potash"), Sodium Hydrate (com- 
monly called " soda," or "caustic soda "), Ammonium Hydrate 
(in the form of solution called "ammonia water," or "caustic 
ammonia," or "spirit of hartshorn"), Barium Hydrate (used in 
volumetric analysis), Calcium Hydrate (in the form of solu- 
tion commonly called "lime water"; in the solid state it is 
called, in common parlance, " slaked lime"), Aluminum. 
Hydrate, and Ferric Hydrate (called "hydrated oxide of iron"). 

878. Table of Common Hydrates with their Molecular Formu- 
las and Molecular Weights. 



Names. 


Formulas. 


Molecular 
Weights* 


Potassium 
Sodium 
Lithium 
Ammonium 

Bismuthyl 

Calcium 
Barium 

with water 
Strontium 

" with water 
Magnesium 


KOH 
NaOH 
Li OH 
NH 4 OH 

BiO.OH 

Ca(OH) 3 

Ba(OH) 2 

Ba(OH) 3 .8H 2 

Sr(OH) 2 

Sr(OH) 2 .8H 2 

Mg(OH) 2 


56 
40 
24 

35 
241.9 

74 
171 

3i5 
121.4. 

265.4 

58.3 



CHEMISTRY. 



249 



Names. 


Formulas. 


Molecular 
Weights. 


Zinc 


Zn (OH), 


99-3 


Cadmium 


Cd (OH). 


146 


Cobaltous 


Co (OH), 


93 


Nickelous 


Ni(OH) 3 


92.7 


Manganous 


Mn(OH) 2 


89 


Ferrous 


Fe(OH) 2 


90 


Copper 


Cu (OH), 


96.4 


Aluminic 


Al 2 (OH), 


156 


Chromic 


Cr a (OH) 6 


206 


Manganic 


Mn 2 (OH) 6 


212 


Ferric 


Fe 2 (OH) 6 


214 


Cobaltic 


Co 2 (OH) 6 


228.4 


Nickelic 


Ni 2 (OH), 


219.4 



879. Basic Hydrates. — By the term "basic hydrate,"which 
is commonly used in works on chemistry and pharmacy, we 
mean a hydrate apparently combined in some way with the 
oxide of the same metal, as, for instance, the basic ferric hydrate 
which is represented as being Fe 2 3 .Fe 2 (OH) c . 

880. Base residues. — When the replaceable hydrogen of 
a base — the hydrogen of its hydroxyl — is taken from its mole- 
cule, the remainder is called the residue of the base. Thus KO 
is the base residue of KOH. 

881. The saturating power of a base — that is, its power to 
saturate acids — with reference to valence, is indicated by the 
number of hydroxyl groups contained in its molecule. As 
hydroxyl is a monad group, it follows that each such group is 
united to the positive element or radical by one bond, and that 
the base is capable of satisfying as many valence units of any 
acid radical as there are hydroxyl groups in the basic molecule. 

The number of hydroxyl groups in any base is expressed by 
the term acidity. A base with one hydroxyl group is said to be 
mon-acid because it satisfies but one acid valence unit: a base 



250 CHEMISTRY. 

with two hydroxyl groups is di-acid, for it has the power of sat- 
urating a molecule of an acid having a bivalent acid radical, or 
of saturating two molecules of a mono-basic (885) acid; etc. 

882. When a base is saturated by an acid, and a salt thus 
formed, the hydroxyl of the base is replaced by an acid radical. 
Thus KOH saturated by HN0 3 becomes KNO s . 



CHAPTER XLVII. 



ACIDS. 

883. Acids are the salts of hydrogen. They are of two 
classes: 1, Hydroxyl Acids, and 2, Hydrogen Acids. 

All the so-called strong acids, by which expression is meant 
soluble acids exhibiting such chemical energy that they readily' 
react with metals or metallic oxides, have a sour or acid taste, 
and turn blue litmus and certain other blue vegetable colors 
red. 

All acids combine with bases and metallic oxides forming 
salts (992), water being simultaneously formed. 

Several acids are so energetic as to attack and dissolve metals, 
metallic oxides, hydrates and carbonates, and to decompose 
sulphides, etc. 

All acids contain positive hydrogen. This hydrogen can be 
replaced by other positive radicals, as by metals and certain 
compound radicals. In the acid the positive hydrogen is 
united directly or indirectly to a negative radical, elemental or 
compound. 

Hydrogen is such a weak positive radical that it readily 
yields its place to other positive radicals. Each acid contains 
one or more atoms of hydrogen which can thus be replaced. 

The acid properties of hydrogen salts, their energy in attack- 



CHEMISTRY. 251 

ing other substances, and their utility as materials for the pro- 
duction of various other compounds, depend upon the weak 
character of their positive radical — the hydrogen. 

Any acid molecule may be split up into two parts — its 
replaceable hydrogen alone forms one part, and all of the remainder 
is called an acid-residue ■, or acid-radical. 

Sulphuric acid, nitric acid, phosphoric acid, hydrochloric 
acid, hydrobromic acid, and oxalic acid, tartaric acid, citric acid, 
and acetic acid are among our most characteristic and pro- 
nounced acids, and the six first named are so extremely corro- 
sive and destructive that they must be handled with great care. 

884. Hydroxyl acids. A hydroxyl acid is a molecule con- 
sisting of a negative radical united to hydroxy L 

Hydroxyl acids are very numerous. As the hydrogen of the 
hydroxyl can be exchanged for other positive radicals, each 
hydroxyl group represents one valence unit of the residue (883). 
In other words, the number of hydroxyl groups in any acid 
determines its basicity (885). 

Hydroxyl acids are also frequently called "true acids," or 
"oxy-acids," or " oxygen-acids," to distinguish them from hydro- 
gen acids. 

885. The Basicity of an acid is the valence of its residue or 
acid-radical. It is so called because it indicates the power of 
the acid to saturate bases by satisfying the valence units of the 
positive radical of the base. 

Thus an acid having but one hydroxyl group in its molecule 
is monobasic, as it contains but one basic hydrogen atom; an acid 
containing two hydroxyl groups and, therefore, two basic hydro- 
gen atoms, is a bibasic acid; an acid with three hydroxyl groups, 
or having a trivalent acid-radical, is tribasic; and if the acid has 
four hydroxyl groups, is tetrabasic, because its radical is capable 
of saturating four basic valence units, or has four replaceable 
positive or basic hydrogen atoms 

886. The most common hydroxyl acids are the following: 
(See also 809.) 



252 CHEMISTRY. 










' '-0 








^| 8 « 




Name. 


Formula. 


v > ^ a» 


Basicity. 


Hypochlorous Acid 


HCIO 




Monobasic 


Chloric Acid 


HCIO3 




<< 


Iodic Acid 


HI0 3 




« 


Nitrous Acid 


HN0 2 




« 


Nitric Acid 


HNO3 




u 


Hypophosphorous Acid 


HH 2 PO., 




a 


Metaphosphoric Acid 


HPO3 




u 


Acetic Acid 


HQH 3 2 




C( 


Valeric Acid 


HC 5 H 9 2 




u 


Lactic Acid 


HC 3 H 5 3 




u 


Oleic Acid 


HQsHggO., 




a 


Phenyl-Sulphonic Acid 


HQH 5 SOj 


<t 


Salicylic Acid 


HC 7 H 5 3 




u 


Benzoic Acid 


HC 7 H 5 2 




a 


Sulphurous Acid 


H 2 S0 3 


2 


Bibasic. 


Sulphuric Acid 


H 2 SO ± 


2 


" 


Thiosulphuric Acid 


H 2 S,0 3 


2 


(< 


Phosphorous Acid 


H 2 HPO a 


2 


tc 


Arsenous Acid 


H 2 HAsO, 


2 


u 


Antimonous Acid 


H 2 HSbO s 


2 


* " 


Carbonic Acid 


H 2 C0 3 


2 


a 


Oxalic Acid 


HaQO, 


2 


a 


Silicic Acid 


H 2 SiO a 


2 


a 


Stannic Acid 


H 2 SnO s 


2 


a 


Pyroboric Acid 


H 2 B,0 7 


2 


a 


Tartaric Acid 


g*QH 4 o 6 


2 


(1 


Succinic Acid 


HaQH.O, 


2 


u 


(Ortho-) Phosphoric Acid 


H3PO, 


3 


Tribasic. 


(Ortho-) Arsenic Acid 


HsAsOi 


3 


<< 


Boric Acid 


H 3 B0 3 


3 


C( 


Citric Acid 


H 3 QH 5 7 


3 


u 


Malic Acid 


H 3 C 4 H 3 5 


3 


li 


Pyrophosphoric Acid 


H 4 P 3 7 


4 


Tetrabasic 


Pyroarsenic Acid 


H.ASoO; 


4 


a 



CHEMISTRY. 253 

887. Reactions of Bases and Acids with each other.— We 
have seen that bases and acids are both hydroxyl compounds. 
It has also been stated that acids and bases react upon each 
other, forming salts, and at the same time water. It may be 
added that we can look at this double decomposition in several 
different ways: while it is commonly said that the basic hydro- 
gen of the acid molecule is replaced by the positive radical of 
the base, we could with equal propriety say that the negative 
hydrogen of the base is replaced by the acid-forming radical of 
the acid, or that the hydroxyl of the base is replaced by the 
acid-residue or acid radical, or that the hydroxyl of the acid is 
replaced by the base residue. Thus — 

KOH + HNO3 = KNO3 + H'O may be explained in either 
of the four different ways, for we can say that the HN0 3 has 
exchanged its H for K; or that the H of the KOH has been 
exchanged for the N0 2 , which together with HO -forms the 
HN0 3 ; or that the OH of the base has been replaced by N0 3 ; 
or that the hydroxyl group of the acid has been exchanged for 
KO. 

It may also be said that when a base and a hydroxyl acid 
neutralize each other, the positive radical of the base unites with 
the negative acid radical, while the hydroxyl of the base unites 
with the positive hydrogen of the acid to form water. 

888. Hydrogen Acids are the compounds of positive 
hydrogen with the halogens. They are also called hydracids. The 
hydrogen is replaceable by other positive radicals, resulting 
in the formation of haloids (859). 

The hydrogen acids are all monobasic, because they all con- 
tain but one hydrogen atom. They are as follows: 

Names. Fontiulas. 

Hydrofluoric Acid HF 

Hydrochloric Acid HO 

Hydrobromic Acid HBr 

Hydriodic Acid Hi 

Hydrocyanic Acid HCN 



254 CHEMISTRY. 

889. When a hydrogen acid and a base neutralize each 
other, the hydrogen of the acid unites with the hydroxyl of the 
base, while the halogen of the acid unites with the positive 
element or group of the base: 

K0H+HC1==KC1+H 2 0. 

890. The action Of acids on metals. — Hydrochloric acta 
dissolves zinc, aluminum, iron, nickel and tin; but does not attack 
lead, copper, mercury, silver, arsenic, antimony and bismuth. 

When a metal is dissolved in hydrochloric acid, the hydrogen 
of the acid is always liberated, while the metal is turned into a 
chloride. 

Sulphuric acid, diluted, attacks and dissolves zinc, iron and 
nickel, forming sulphates; dilute sulphuric acid does not attack 
aluminum, lead, copper, mercury, silver, arsenic, antimony and 
bismuth. The hydrogen of the acid is liberated, being displaced 
by the metal. 

Concentrated sulphuric acid attacks copper, and, if hot, it 
also attacks mercury, silver and bismuth. In these cases a por- 
tion of the acid is decomposed into hydroxyl and S0 2 , and 
another portion into hydrogen and S0 4 ; the S0 2 passes off as a 
gas, the hydroxyl forms water with the hydrogen, and the metal 
forms sulphate with the S0 4 , so that the products of the reaction 
are three. 

Nitric acid, when cold and dilute, dissolves zinc and iron with 
the formation of nitrates of the metals together with ammonium 
nitrate, the latter salt resulting from the decomposition of a 
portion of the acid by the nascent hydrogen replaced by the 
metal. Strong nitric acid does not attack iron. 

When warm dilute nitric acid attacks zinc, iron, nickel, lead, 
copper, mercury, silver, arsenic and bismuth, the acid radical 
itself is decomposed, either N 2 2 or N 2 4 being formed and red 
fumes given off. 

Strong nitric acid acting upon tin forms insoluble metastan- 
nic acid; antimony is oxidized by strong nitric acid to insoluble 
antimonous oxide. 



CHEMISTRY. 255 

Gold and Platinum are not attacked by any acid, but are dis- 
solved by aqua regia. Aluminum is attacked by hydrochloric 
acid; silver by nitric acid. 

The following equations represent the reactions which take 
place between acids and metals as described: 

891. Strong acids dissolve metallic oxides, hydrates and 
carbonates in all cases where the new salt thus formed is water 
soluble. Thus we have: — 



Mg O 


+ H 2 S0 4 


= Mg S0 4 


+ H 2 O 


Zn O 


+ 2H C 2 H 3 2 


= Zn (C 2 H 3 2 ) s 


+ H 2 


Pb O 


+ 2H N0 3 


- Pb (N0 3 ) 2 


+ H 2 


HgO 


+ 2H N0 3 


= Hg (N0 3 ) 2 


+ H 2 O 


Fe 2 3 


+ 6H CI 


= Fe 2 CI. 


+ 3H 2 


Mn 2 


+ 4H CI 


= Mn Cl a 


+ CI, ■»- 2H 2 


Bi 2 3 


+ 6H N0 3 


— 2Bi (N0 3 ) 3 


+ 3H 2 


2Na OH t- H 2 SO, 


— Na 2 SO, 


+ 2H 2 O 


Al a -(OH) 6 + 6H N0 3 


- Al, (N0 3 ) 6 


+ 6H 2 O 


Fe 2 (OH) 6 + 6H CI 


= Fe 2 CI. 


+ 6H 2 O 


Ca (OH) 2 + 2H N0 3 


= Ca (N0 3 ) 2 


+ H 2 O 


Ca C0 3 


+ 2H CI 


= Ca Cl 2 


+ H 2 O +C0 2 


Li C0 3 


+ H Br 


= Li Br 


+ CO, 


Fe 2 


+ 4H CI 


= 2Fe Cl a 


f-2H 2 


Al a 


+ 6H CI 


= Al, CI. 


I-3H, 


Sn 2 


+ 4H CI 


= 2Sn Cl 2 


+ 2H 2 


Zn 2 


+ 2H 2 SO, 


= 2Zn SO, 


+ 2H 2 


Fe 2 


+ 2 H 2 SO, 


= 2 Fe SO, 


+ 2H 3 


Cu 2 


+ 4H 2 SO, 


— 2Cu SO, 


+ 4 H 2 0+. 2S O a 


3Cu 2 + 


6H 2 SO,+ 4 H 1 


S[Of= 6Cu SO,+ 8H 2 Of- 2N 2 2 


Hg. + 


4H 2 SO, 


= 2 Hg SO,+ 


4 H 2 Of- 2S 2 


2Fe 2 + 


10H NOf= NH 4 NOo + 4Fe 


(N0 8 )g+ 3 H 2 O 


Fe 2 + 


8H N0 3 =2Fe (N0 3 ) 2 + 4H 2 


O + 2N 2 O, 


5Sn 2 + 


40H NOj= 2(H 4 SnOi + 2oN 2 


O, 


Sb 2 + 


2H N0 3 = Sb 2 O3 + N 2 O s + Hg ( 



256 CHEMISTRY. 

CHAPTER XLVIII. 

' SALTS. 

892. Salts are neutral compounds consisting of a metal or 
other positive radical united to an acid radical or to a halogen. 
They -are produced by the action of acids upon metals, oxides, 
hydrates and carbonates, and sometimes by other means. Insol- 
uble salts are generally produced by double decomposition of 
soluble salts. 

Salts may be regarded as formed by replacing the basic 
hydrogen of an acid by some other positive radical; or by 
replacing the hydroxyl of an acid by a base-residue; or by 
replacing the oxvgen of a basic oxide (848) by an acid radical 

(815)- 

The reactions presented in the two preceding paragraphs 
illustrate the formation of salts by the action of acids upon 
metals, oxides, hydrates and carbonates. 

893. Salt radicals. — Salts may be regarded as consisting 
of two opposite kinds of radicals — -positive salt radicals, which are 
either metals or other salt-forming positive radicals such as the 
compound radicals NH 4 , CH 3 , C 2 H 5 , C 6 H n , BiO, SbO, etc. 
(810 and 811); and negative salt radicals, which are the acid radi- 
cals (or acid residues) and the halogens. 

894. Normal Salts (sometimes called neutral salts) are 
salts in which the acid radical is wholly saturated by any posi- 
tive salt radical or radicals other than hydrogen. It is formed 
when all of the basic (or replaceable) hydrogen of an acid is 
replaced by one or more metals, or by any other positive salt 
radical. A normal salt results when an acid is saturated or 
neutralized by a base, or by a basic oxide. Thus, a normal salt 
does not contain any hydrogen that can be replaced by a metal 
or other positive radical. Each acid can form but one normal 
salt with each base. 

895. Acid Salts are salts containing replaceable basic 
hydrogen, or salts in which the valence units of the acid radical 
are only partly neutralized by a salt radical, the remaining 



CHEMISTRY. 



: 57 



valence unit or units being united to hydrogen. They are 
formed when an acid containing more than one atom of replace- 
able hydrogen (more than one hydroxyl group) retains one or 
more of these hydrogen atoms, the other basic hydrogen atom 
or atoms being replaced by one or more salt radicals. 

896. Thus monobasic acids (885) can not have any acid 
salts, but bibasic acids can each have one normal and one acid 
salt, and tribasic acids can have one normal and two different 
acid salts, with each monacid base. 

897. As nitric acid and hydrochloric acid are both mono- 
basic (885), they have no acid salts, and their normal salts have 
formulas like the following : 

KNO3 Pb(N0 3 ) 2 Bi(N0 3 ) 3 

KC1 PbCl 2 BiCl 3 

Sulphuric acid, carbonic acid and tartaric acid are bibasic, 
and they can, therefore, have each one normal and one acid salt 
with each monacid base : 

K 2 SO, CaS0 4 Fe 2 (S0 4 ) s . 

KHSO, 

K 2 C0 3 CaCo 3 

KHCO s 

K 2 QHA 
KHQH 4 6 
Phosphoric acid and citric acid are tribasic, and we, therefore, 
have : 

NasPO, Na 2 HP0 4 NaH 2 P0 4 

Na 3 C 6 H 5 7 Na 2 HC 6 H 5 7 NaH 2 C 6 H 5 7 
Ca 3 (PO,) 2 CaH*(POJ 2 CaHPO,. 

898. Basic Salts. — There are some compounds which seem to consist of 
a normal metallic salt combined with the hydrate or oxide of the same metal. 
These are called basic salts. Thus we have basic acetate of copper (verdigris), 
basic acetates of lead (of which the compound contained in solution of sub- 
acetate of lead is an example), basic acetate of iron, basic sulphates of iron 
(in Monsel's solution) and of mercury (yellow sulphate of mercury or turpeth 



258 CHEMISTRY. 

mineral), basic nitrates of mercury and basic carbonates of magnesium, zinc 
and lead. The molecular formulas given for some of these basic salts are as 
follows: 

Magnesium Carbonate = (MgC0 3 ) 4 . Mg(OH) 2 . 5H 2 0. 

Zinc Carbonate = (ZnC0 3 ) 2 . 3Zn(OH) 2 . 

Lead Carbonate = (PbC0 3 ) 2 . Pd(OH) 2 . 

Ferric Subsulphate = Fe 4 0(S0 4 )5. 

Basic Mercuric Sulphate = (HgO) 2 HgS0 4 . 

Basic Lead Acetate == Pb(C 2 H 3 2 ) 2 . Pb(OH) 2 . 

Basic Cupric Acetate ==C u 2 0(C 2 H 3 2 ) 2 . 

899. Double Salts. — Salts containing two different positive 
salt radicals united to one negative salt radical (893) are called 
double salts. 

If a bibasic acid exchanges one of its basic hydrogen atoms 
for one metal and the other hydrogen atom for another metal, 
the result is a double salt. Thus, sulphuric acid, H 2 S0 4 , may 
form KNaS0 4 ; tartaric acid, H 2 C 4 H 4 6 , forms KNaC 4 H 4 6 , and 
KSbOC 4 H 4 6 ; and the alums are also double salts: 

A1 2 K 2 (S0 4 ) 4 , 

A1 2 (NH 4 ) 2 (S0 4 ) 4 , and 

Fe 2 (NH 4 ) 2 (S0 4 ) 4 . 
The scale salts of iron called citrate of iron and ammonium, citrate of 
iron and quinine, tartrate of iron and ammonium, tartrate of iron and potas- 
sium, phosphate of iron and pyro-phosphate of iron (both combined with 
sodium citrate), are not true double salts' 

900. Oxy salts are the salts produced by hydroxyl acids or 
their acid radicals. Haloids are also commonly referred to as 
"salts'' (859), although the definition just given, which is now 
generally accepted by many chemists, excludes them. In this 
book the definition of salts (892) includes the haloids, and the 
term will be used as applicable to both oxy-salts and haloids. 
Nevertheless we have placed the several groups of haloids by 
themselves by way of emphasizing the difference between 
haloids and oxy-salts. 

The principal groups of oxy-salts of inorganic chemistry are 
the nitrates, chlorates, hypochlorites, sulphates, sulphites, phos- 



CHEMISTRY. 259 

phates, hypophosphites, carbonates and silicates. But there are 
also very important groups of salts formed by the organic acids 
with inorganic bases; these groups are: Acetates, valerates, 
lactates, oleates, oxalates, tartrates, citrates, phenyl-sulphonates, 
salicylates and benzoates. 



CHAPTER XLIX. 



NITRATES, CHLORATES, ETC. 



901. Nitrates are the salts formed by nitric acid, or the 
salts containing the characteristic group N0 3 . This acid-radical 
(N0 3 ) is a monad. 

The nitrates of 7nercury and bismuth are split up by water into 
insoluble basic salts and acid; they can, therefore, not be dis- 
solved in water alone, but are soluble in water containing a large 
amount of nitric acid. All other nitrates are water-soluble. 

The metallic nitrates may be prepared by saturating nitric 
acid with the metals, or their oxides, hydrates, or carbonates, or 
by double decomposition if the bye-product (1026) be insoluble. 
Even the nitrates of mercury and bismuth are prepared by dis- 
solving these metals in nitric acid, but an excess of nitric must 
then be used to retain the nitrates in solution. 

902. The nitric radical (N0 3 ) is an unstable group, easily 
giving up a portion of its oxygen. The decomposition of the 
nitrate radical takes place both in nitric acid and in other 
nitrates whenever a radical having a strong affinity for oxygen 
is brought in contact with them. Nitric acid and sometimes 
other nitrates are, therefore, used as oxidizing agents (1006). The 
decomposition referred to is generally rapid and accompanied 
by the evolution of a colorless gas, N 2 2 , which, however, 
immediately changes in the air to N 2 0±, which is red. Red fumes 
accordingly make their appearance on dissolving metals in 



260 



CHEMISTRY. 



nitric acid. The application of heat hastens the decomposition 
of the nitric acid or the nitrate, and therefore, also the simul- 
taneous oxidation (667) of the radical, which, by its affinity for 
oxygen, helps to cause the reaction. That radical is frequently 
the hydrogen of the nitric acid itself, as in — 

3Cu 8 +i6HNO»=6Cu(NO s ) 8 +2N a O J |+8H s O. 
The oxygen removed from the nitrate radical is utilized 
directly or indirectly to change certain -ous compounds to -ic coin- 
pounds (989 to 991). 



903. The officinal nitrates are those of hydrogen (called nitric 
acid), potassium (called " nitre" or "saltpetre"), sodium (called 
"Chile-saltpetre") ammonium, silver (called "lunar caustic" 
when fused and molded into sticks), bismuthyl (called "sub- 
nitrate of bismuth"), barium (used as a reagent), mercuric 
mercury (contained in the "solution of nitrate of mercury"), 
lead, and ferric iron (in the " solution of nitrate of iron "). 

904. The following table contains the — 

Common Nitrates, with their Molecular Formulas and Molecular 
Weights. 



Names. 


Formulas. 


Molecular 
Weights. 


Hydrogen (nitric acid) 

Potassium 

Sodium 

Ammonium 


HXO3 
KNO a 

XaXG 3 

NH,\'0 :i 




63 

IOI 

85 

80 


Silver 


AgX0 3 




169.7 


Bismuthyl 


BiO.X0 3 . 


H 2 


3°5 


Mercurous 

" with water 


Hg^X0 3 ) 
HgiXG 3 ) 


2.2H 2 


524 
55o 


Calcium 

" with water 


CafXO k 
CaX0 3 ) 2 


. 4 H 2 


164 
236 



CHEMISTRY. 



26l 



Names. 


Formulas. 


Molecular 
Weights. 


Barium 


Ba(N0 3 ) 2 


261 


Strontium 


Sr(N0 3 ) 2 


211. 3 


Magnesium 


Mg(N0 3 ) 2 


148.3 


with water 


Mg(N0 3 ),6H 2 


2 5 6 -3 


Zinc 


Zn(N0 3 ) 2 


189 


Mercuric 


Hg(N0 3 \ 


3 2 4 


Cupric 


Cu(N0 3 ) 2 


187.2 


" with water 


Cu(N0 3 ),3H 2 


241.2 


Lead 


Pb(NO a ) a 


330-4 


Manganous 


Mn (N0 3 ), 


179 


with water 


Mn (N0 3 )*6H 2 


287 


Ferrous 


Fe (NO,), 


180 


Cobaltous 


Co(N0 3 ) 2 


183 


with water 


Co(NO0,6H 2 O 


291 


Nickelous 


Ni(NO s ) 2 


182.6 


with water 


Ni(N0 3 ) 2 6H 2 


290.6 


Bismuthous 


Bi(N0 3 ) 3 5H 2 


485 


Cerium 


Ce 2 (NO 3 ) 


652 


Aluminum 


Al 2 (NO 3 ) 


426 


with water 


Al 2 (NO 3 ) i8H 2 O 


75° 


Ferric 


Fe 2 (N0 3 ) c 


484 


Cobaltic 


Co 2 (N0 3 ) 6 


490 



905. Chlorates are the salts containing the radical C10 3 . 
The chlorates of potassium and sodium are officinal. These 
salts are unstable, exploding violently by percussion or by tritu- 
ration with sulphur, tannin, sugar, etc. 

Potassium chlorate is soluble in about 16 times its weight of 
water at common room temperatures, and sodium chlorate in 
about its own weight. They may be prepared by passing 



262 CHEMISTRY. 

chlorine into solutions of the hydrates, by which hypochlorites 
are first formed and these afterwards decomposed by heat — 
6KOH + 3 C1 2 = 3KCIO + 3KCI + 3H 2 0; and then 3KCIO = 
KCIO3 + 2KCI. 

Instead of the alkali hydrate a mixture of calcium hydrate 
with the chloride of the alkali metal is now generally employed. 

The formulas and molecular weights are — 

Potassium Chlorate = KCIO3 = 122.4 

Sodium Chlorate = NaC10 3 = 106.4 

906. Hypochlorites contain CIO. They are unstable, 
yielding chlorine upon the addition of acids, or even without 
that addition, The "chlorinated lime," commonly called 
"chloride of lime" and "bleaching powder," depends upon its 
hypochlorite of calcium for its effects, and " Labarrao^ae's Solu- 
tion" ("solution of chlorinated soda") and Eau de Jarelle (con- 
taining potassium hypochlorite) are similar. They are used as 
disinfectants and for bleaching cotton and linen. 

Potassium Hypochlorite = KCIO = 90.4 

Sodium " =NaC10== 74.4 

Calcium " = CaCIO = 142.8 



CHAPTER L. 



SULPHATES AND SULPHITES. 



907. Sulphates — The sulphate radical is S(\, and it is a 
dyad. Sulphuric acid is, therefore, a bibasic acid. Sulphuric 
acid decomposes the salts of other acids, as a rule, and may be 
considered as the " strongest " of all the acids. The great energy 
with which sulphuric acid attacks other substances, or its 
extremely destructive effects, may be regarded as the resultant 



CHEMISTRY. 



263 



of the chemical union of so powerful a negative radical as S0 4 to 
so weak a positive radical as hydrogen, and the ever present 
strong tendency of the acid radical to exchange the hydrogen 
for a more strongly positive element or group. Thus sulphuric 
acid may be considered an unstable compound, while the sul- 
phates of the strongest electro-positive radicals are among the 
most stable of all compounds. 

908. Solubility. — The sulphates of lead, barium and strontium 
are insoluble in water. Calcium sulphate is very sparingly 
water-soluble. Sulphate of mercury is decomposed by water. 
The other officinal metallic sulphates are water-soluble. 

909. Preparation. — The soluble metallic sulphates, and also 
mercury sulphate, are made by the action of sulphuric acid 
upon the metals or their oxides, hydrates, carbonates, or chlo- 
rides, and the alkali sulphates are often obtained as by-products 
in the preparation of other salts. The insoluble sulphates are 
obtained by double decomposition as precipitates. 

910. The officinal sulphates are many, and are included in 
the following 

Table of Com??ion Sulphates with their molecular formulas and 
molecular weights: 



Names. 


For??iulas. 


Molecular 
Weights. 


Hydrogen(sulphuric acid) 


H 2 SO, 


98 


Potassium, normal 


k 2 so; 


174 


Potassium, acid 


KHS0 4 


136 


Sodium, normal 


Na 2 S0 4 


142 


Sodium, normal, cryst. 


Na 2 S0 4 .ioH 2 


322 


Sodium, acid 


NaHS0 4 


120 


Ammonium 


(NH,) 2 S0 4 


132 


Calcium 


CaS0 4 


136 


" with water 


CaS0 4 . 2 H g O 


172 


Barium 


BaS0 4 


2 33 


Strontium 


SrS0 4 


183.3 


Magnesium, anhydrous 


MgSQ 4 


120.3 



264 



CHEMISTRY 



Names. 


Formulas. 


Molecular 
Weights, 


Magnesium, dried 


MgS0 4 . 2 H 2 


T 56.3 


" cryst. 
Zinc 


MgS0 4#7 H 2 
ZnS0 4 


246.3 
161 


" cryst. 


ZnS0 1>7 H 2 


287 


Ferrous, anhydrous 


FeSO, 


*5 2 


dried 


FeSO,.H 2 


170 


" cryst. 


FeS0 4 . 7 H 2 


278 


Manganous 


MnSO. 


I 5 1 


cryst. 


MnS0 4 . 7 H 2 


223 


Cupric 


CuSO, 


159.2 


" cryst. 


CuS0 4 . 5 H a O 


249.2 


Mercuric 


HgS0 4 


296 


Aluminum 


ai;(soj 3 


342 


" with water 


Al 2 (SO i ) 3 .i8H 2 


666 


Potassa alum 


K 2 Al 2 (SO i ) 4 . 24 H 2 


948 


Dried alum 


K^A^SO,), 


5i6 


Ammonia alum 


( NH 4 ) 2 Al 2 (SO i ) i . 24 H 2 


906 


Ammonio-ferric alum 


(NHJ 2 A1 2 (S0 4 ) 4 . 24 H 2 
Fe 2 (SD 4 ) 3 


964 


Ferric Sulphate 


400 


Ferric sulphate, basic 


Fe 4 6(S0 4 ) 3 


73o 


Mercuric, ba_sic 


(HgO) 2 .HgSO, 


728 



911. Thiosulphates. — The only thiosulphate of interest to 
pharmacists is the so-called " hyposulphite of sodium," which 
has the formula Na 2 S20 3# ^H 2 and the molecular weight 248. 

912. Sulphites are characterized by containing the radical 
•5^3* which is bivalent. Sulphites are reducing agents, being con- 
verted into sulphates by taking up more oxygen. They are not 
freely soluble in water, and are generally prepared by the action 
of S0 2 upon hydrates, or carbonates. The solution obtained by 
passing the gas S0 2 into water is properly regarded as contain- 
ing sulphurous acid, and is so named in the Pharmacopoeia. 



CHEMISTRY. 265 

913. The common sulphites with their molecular formulas and 
weights are: 



Names. 




Formulas. 


Molecular 










Weights. 


Hydrogen 


(su 


Iphurous 


H 2 S0 3 


82 


acid) 










Potassium 






K 2 S0 3 .2H 2 


194 2 


Sodium 






Na 2 S0 3 .7H 2 


252 


Calcium 






CaS0 3 .2H 2 


156 


Magnesium 






MgSO .6H2O 


212.3 



CHAPTER LI 



PHOSPHATES, ETC 

914. Phosphates (ortho-phosphates). — The acid radical 
which forms the ortho-phosphates is the group P0 4 , which acts 
as a triad, so that ortho-phosphoric acid is tribasic. The phos- 
phates are very stable compounds, for the phosphate radical is 
a powerful negative radical. 

The phosphates of potassium, sodium and ammonium are 
water-soluble ; all other phosphates are insoluble in water. Ferric 
phosphate is soluble in solutions of citrates of potassium, 
sodium or ammonium, and the "phosphate of iron " of the 
Pharmacopoeia is a compound consisting of the water-soluble 
scaled residue obtained from a solution of ferric phosphate in 
solution of sodium citrate. 

The soluble phosphates may be produced by the action of 
phosphoric acid upon hydrates or carbonates, but all phosphates 



>66 



CHEMISTRY. 



are generally prepared by double decomposition. Phosphates 
of calcium, iron and some other phosphates which are insoluble 
in water, dissolve in ortho-phosphoric acid. Hence phosphate 
of iron can be made by the action of phosphoric acid upon 
iron. 

The phosphoric acid of the Pharmacopoeia is ortho-phos- 
phoric acid. 

915. The officinal phosphates are all contained in the follow- 
ing 

Table of Common Phosphates with their. Molecular Formulas and 
Molecular Weights: 



Names. 



Phosphates. 

Hydrogen (ortho-phos- 
phoric acid) 

Potassium 

Sodium 

" crvst. 



Microcosmic salt 
Ammonium 



Calcium 



Acid 



Manganous 
Ferrous 

Manganic 
Ferric 



Ferroso-ferric 



Formulas. 



H 3 P0 4 
K 2 HPO ± 
Na 2 HPO, 
N^HPO^HjjO 

NH 4 NaHP0 4 . 4 H a O 

(NH 4 ) 2 HPO, 

Ca s (P0 4 ) 2 
CaH 4 (PO,) a 

MnslPCg^H-jO 
Fe 3 (P0 4 ) 2 .8H 2 

Mn 2 (P0 4 ) 2 . 4 H 2 
Fe 2 (PO i ) 24 H 2 

2Fe 3 (PO i ) 3 .Fe 2 (P0 4 ) 2 . 24 H 2 



i Molecular 
i Weights. 



98 
174.2 

1 4 2 

358.1 

4 i8 
132 

310 
234 

481 

502 

425.9 
374 

i45°- 2 






CHEMISTRY. 267 

916. Metaphosphates. — The so-called "glacial phosphoric 
acid " is meta-phosphoric acid more or less contaminated with 
pyrophosphoric acid and with phosphates, as found in com- 
merce. 

The relations of meta-phosphoric, ortho-phosphoric and 
pyro-phosphoric acid to each other are shown by these equations: 

2HPO3 + H 2 = H 4 P 2 7 

Meta-phosphoric acid Water Pyrophosphoric acid; and- 

H 4 P 2 7 + H 2 G = 2H 3 FO, 

Pyrophosphoric acid Water Orthophosphoric acid 

Metaphosphoric acid is changed to orthophosphoric acid by 
being boiled in water. 

Ferric metaphosphate and ferric pyrophosphate are insoluble 
in ortho-phosphoric acid, but soluble in metaphosphoric acid. 

Metaphosphoric acid is HPO s = 80. 

917. Pyrophosphates contain the radical P 2 7 ,- which acts 
as a tetrad. Pyrophosphate of sodium is formed when phos- 
phate of sodium is heated strongly; but the pyrophosphate is 
not decomposed even at extremely high temperatures. 

Insoluble pyrophosphates are made by double decomposition 
from pyrophosphate of sodium. 

Crystallized sodium pyrophosphate is Na 4 P:0 7 ,ioH 2 = 446.1; 
dried sodium pyrophosphate is Na 4 P 3 : = 266; ferric pyrophos- 
phate is Fe 4 (P 2 7 ) 3 = 746. 

Ferric pyrophosphate is insoluble in water, but soluble in 
diluted metaphosphoric acid; it is also soluble in solutions of 
alkali citrates, and the pharmacopoeial "pyrophosphate of iron " 
is the water-soluble scaled residue obtained from a solution of 
ferric phosphate in solution of sodium citrate. 

918. Hypophosphites contain the group HoPO^ which acts 
as a monad. The hypophosphites of potassium, sodium, cal- 
cium and iron are used as medicines; they are all water-soluble, 
except that the iron hypophosphites are so sparingly soluble as 
to be practically nearly insoluble. 



268 CHEMISTRY. 

Calcium hypophosphite is produced by boiling phosphorus 
with calcium hydrate; the others are prepared from the calcium 
hypophosphite or from the sodium salt. 

The formulas and molecular weights of the officinal hypo- 
phosphites are: 

Hypophosphorous Acid = H H 2 P0 2 = 66. 
Potassium Hypophosphite = K H 2 P0 2 = 104. 
Sodium " = Na H. 2 PO.> = 106. 



Calcium " = Ca (H 2 P0 2 ) 2 = 170. 



Ferrous " = Fe (H 3 P0 2 ), = 186. 



Ferric " = Fe 2 (H 2 P0 2 ) 6 = 502. 



CHAPTER LII. 

CARBONATES, ETC. 



919. Carbonates are the salts containing the group CO? 
which is bivalent. They are easily decomposed by acids, the 
gas C0 2 being given off with effervescence. The carbonates of 
the alkali metals are the only carbonates not decomposed by 
heat. Sodium carbonate and potassium carbonate are pro- 
duced in immense quantities by heating the sulphate with chalk 
and coal. Insoluble carbonates are prepared from the soluble 
carbonates by double decomposition. 

Acid carbonates are commonly called " bicarbonates." Mag- 
nesium, zinc and lead form "basic carbonates." 



CHEMISTRY. 



269 



O20. Table of Common Carbonates with their Molecular Formulas 
and Molecular Weights: 



Names. 


Formulas. 




Molecular 
Weights. 


Hydrogen (carbonic acid) 


H 2 CO s 




62 


Potassium, anhydrous 


K 2 CO s 




138 


" ordinary 


2K 2 C0 3 . 3H 2 




330 


" acid 


KHCO3 




100 


Sodium, anhydous 


Na 2 C0 3 




106 


" dried 


Na 2 C0 3 .2H 2 




142 


" cryst. 


Na 2 COo ioH 2 




286 


11 acid 


NaHC0 3 




84 


Lithium 


Li 2 C0 3 




74 


Ammonium, normal 


(NH,),C0 3 




96 


" acid 


NH 4 HCO s 




79 


" officinal 


NH 4 HC0 3 . XH 4 XH 3 CO s 
(BiO) 2 C0 3 . H 2 0. 
CaC0 3 


157 


Bismuthyl 


528 


Calcium 


100 


Barium 


BaC0 3 




197 


Manganous 


MnCO s 




"5 


Ferrous 


FeC0 3 . H 2 




J 34 


Magnesium 


4 MgCO,. Mg(OH). 


• 5H 2 


487-5 


Zinc 


2ZnCO s . 3Zn(OH). 




548.5 


Lead 


2 PbCO-.Pb(OH)- 




774-9 



921. Borates. — Boric acid is H3BO3 = 62. No normal 
borates are used. Borax or " borate of sodium " is a pyro- 
borate^agBiOr.ioHaO = 382.1. Both boric acid and borax are 
water-soluble. 

922. Silicates contain the radical 5i0 3 , which is analogous 
to C0 3 and of the same exchangeable value. The silicates of 
potassium and sodium are water-soluble; all others insoluble 



CITOnSTRY. 

dium silicate is called " water-glass.' 



Fir.: glass is silicates of lead of potassium; crown glass consists 
of silicates of sodium and calcium, and Bohemian glass chiefly 
>f silicates )f potassium and calcium . The formulas and molec- 
uiar -"'r:^:5 ::' :;.: z r;n:ic ?.'. siii:a:es are: 

?::_ss:a~ Siliz^e = K ; = if-.; 

Sriiurn Silicate =Na*S.. = :::; 

Cai::a~ 5ili:a:e = CaSiO a =116.3 

Lead Silicate = PbSiO, = 282.7 

223. Arsenates have a structure analogous to that of the 
z b : s z hat es. Ort : - a r 5 e r. a : es contain the radical As G # which, 
like PO^ is trivaier.:. Sodium arsenate is an official prepara- 
■.::n ir. : is v.-=:er-s: luizie : :::e :rys:a".l:iri. sziiarr. irser.^:e :s 
NaaHAsO^H^O = 312; the effloresced salt is 

\a : H I i .:H:G = :::: 
and the dried Xa>HAs0 4 = 186. Iron arsenate is sometimes 
used as a medicine; it is usually of the composition 
2Fe 3 (As0 4 ) 2 .Fe 2 (As0 4 ) a .24H 2 = 1714-2. 

924. Arsenites. — When arsenous oxide is dissolved in water 
the solution may be regarded as containing arsenous acid, 

H a AsQ,= 126. 
Arsenite of potassium is contained in "Fowler's Solution," the 
salt being K H A s 3 = 202. 2. 

925 Pyro-arsenare A sodium is formed when sodium 
:r:a: -arsenate is s:r: zzz'.y heated: i: :s -viter-s : .-die ?.z.i it^s the 
formula (dried X^ = 368. 

026. Permanganate ::' z :>tassium, which is so valuable as 
an oxidizing agent, has the formula Kji - =316 and is solu- 

ble in about 16 times its weight of water at ordinary room tem- 
r eratures 

:~~ Normal rzt^ssium chromate is X : ■'.__= 194 and the 
so-called " bichromate of potassium "is K ; = 294. 



CHEMISTRY. 271 

CHAPTER LIII. 

METALLIC SALTS OF THE ORGANIC ACIDS. 

928. Acetates are the salts formed by the acetate radical, 
I 1 which is univalent. All acetates are water-soluble, and 

• hey are generally made from acetic acid and the oxides, 
hydrates or carbonates of metals. Other _:±:-;e5 are made by 
double decomposition. 

929. The Common Acetates with their Molecular Formulas and 
Moleculir Weights are: 



Na 


/ rmulas 


■S '.: : 


Acetates . 






Hydrogen 
Potassium 
Sodium 

" cryst 
Ammonium 


HC na 

KC H 

Na 

Na . ;H,0 

NH 4 


60 

9 8 

:: 

I3 6 


Magnesium 
Zinc 
" cryst 


Mg(C H 1 
Zn 

Zn .5H.O 


I 4 2 -3 
183 

: - 


Lead 

" basic 
Copper 


Pb . ;HX> 
Pb .PbiOH 
Cu(QH s O s ,K_ 


578.4 

199.2 


Aluminum 
Ferric 


AU(OH 


466 



930. Valerates, or "valerianates," contain the radical 
. which is a monad. Those used in medicine and phar- 
macy are water-soluble. 

Valeric acid is = H 

Sodium Valerate is = Na 

Ammonium Valerate is = XH : 



102 

124 
119 



Zinc Valerate is 



= Zn .H : = 2S5 



; HIMISTRY 



Lactates contain the radical They are little 



90 
1 12 
218 
297 



931- 

d sed. 

Lactic Acid = H; ; 

Sodium Lactate = XaC H 

Calcium Lactate = Ca 

Zinc Lactate = Zn ; ;H : 

Ferrous Lactate = Fe -sFFO 

932. Oleates. — The oleate radical is .which is a 
monad. Fats, soaps, and lead plaster are the most familiar 
cieates. All oleates except the soaps are insoluble in water. 
Soft soap consists entirely or chiefly of potassium oleate: hard 
soaps contain almost exclusively sodium oleate; the oleates of 
lead, zinc, iron, copper, and other heavy metals are plasters. 
The liquid fats or fixed oils are mainly oleate of glyceryl. 

Oleic acid is made from fats, and all other oleates from 
either oleic acid or fats. 

933. The Common Oleates are: 



A 2 ma 



Z.7.: 

Mercuric 

Cupric 

Lr£.l 



Bismuth 



Aluminum 

Ferric 



/.">■":-.'-.". 



Hydrogen (oleic acid) 

Potassium 

S Hum 

Silver 
Mercurous 



HC H 

k; h 

NaJ H 

A g ; h 

Zn 

Hg ; 
Cu 

P: 

O a ) 3 

a: : : -o,)« 

Fe ; ; 



Molecular 
Weights. 



282 

3S9 

962 

627 
762 

625 
769 

«>5 

174 

179 



CHEMISTRY. 



273 



934. Oxalates are salts of the oxalate radical . Oxalic 

acid is bibasic. 

The oxalates of potassium sodium and ammonium are water- 
soluble, and made by neutralizing oxalic acid with the alkal 
hydrates or carbonates; all other oxalates are insoluble and 
made by precipitation. 

Oxalic acid is probably the " strongest" of the organic 
acids. 

No oxalates, except the cerium and ferrous, are official, but 
several are officinal. 



Oxalic acid 




= H 2 . = 90 


" 


with water 


= H, 2H0O = 126 


Potassium 


oxalate, normal 


= K, 2H.O == 202 




" acid 


= KH 2H 2 = 162 


Ammonium 




(NHJgC ,H,0 = 142 


Cerium 


ii 


Ce 2 , 9 H 8 0— 706 


Ferrous 


.. 


Fe .H,0 = 162 



935- Tartrates. — The tartrate radical is , and it 

acts as a dyad. Acid tartrate of potassium is contained in the 
juice of grapes and other fruits. In the crude, impure state the 
potassium acid tartrate is called "argols," or " crude tartar;" 
and the pure is called ''cream of tartar," or "bitartrate of 
potassium." All other tartrates are made from the acid tartrate 
of potassium, directly or indirectly. Acid tartrate of potassium 
is only sparingly soluble in water, requiring about 200 times its 
own weight of water at ordinary room temperatures; the acid 
tartrates of sodium and ammonium are also sparingly soluble. 
The acid tartrates form soluble compounds with iron, of which 
the official tartrate of iron and potassium and tartrate of iron 
and ammonium are examples. 



2 74 CHEMISTRY, 

936. The common tartrates are: 



Names. 


Formulas. 


Molecular 
Weights. 


Hydrogen (tartaric acid) 
Potassium, normal 
" acid 


H 8 QH 4 6 

k 2 c :■ 

KH C 4 H,O 


150 
226 
188 


(cream of tartar) 






.Rochelle salt 
Sodium, normal 

" acid 
Ammonium, normal 
acid 


KNaC .HxO 4H 2 
Na 2 C,H.G 2H 2 
NaHC ; H.u H 2 
(NH^QH.Oe 
NH 4 H C 4 H 4 O 


282 
230 
190 
184 

16, 


Potassium Antimonyl 

("Tartar Emetic ") 


2X850 0^0,^0 


664 


Magnesium 


MgQH 4 6 


172 



937. Citrates are the salts formed by the radical C 6 H 5 0^ 
which is trivalent. There are, therefore, three kinds of citrates 
{897). Citric acid is contained in various fruit juices, espe- 
cially those of lemons, limes and currants. Other citrates are 
prepared from citric acid. The citrates are generally water- 
soluble. The water solutions of alkali citrates dissolve ferric 
phosphate, pyrophosphate and hypophosphite, all of which are 
insoluble in water. Bismuth citrate is soluble in ammonia 
water. 

938. The most common citrates are: 



Names . 


Formulas. 


Moleculat 

Weights. 


Hydrogen (Citric Acid) 
Potassium, normal 
Di-Potassium Hydrogen 
Potassium Di-Hydrogen 
Sodium, normal 


h 3 : : .HoO 

K 3 GH,O 7 H 2 
K 8 H C 6 H 5 7 
KH a C 6 H 5 7 

Na 3 CH 5 7 


210 

3 2 4 
286 
248 
258 



CHEMISTRY. 



2 75 



Names. 


Formulas. 


Molecular 
Weights. 


Di-Sodium Hydrogen 


Na 2 H QH 5 7 


236 


Sodium Di-Hydrogen 


NaH 2 QH 5 7 


214 


Ammonium, normal 


(NH 4 ) S C 6 H 5 7 


243 


Di-Ammonium Hydrogen 


(NH 4 ) 2 H C 6 H 6 7 


226 


Ammonium Di-Hydrogen 


NH 4 H 2 C 6 H 5 7 


209 


Lithium, normal 


Li 3 C 6 H 5 7 


210 


Magnesium, normal 


Mg 3 < C 6 H B 7 ) 2 


450-9 


" acid 


MgH C«H 6 7 


214.3 


Ferric 


Fe 2 (C c H 6 7 )*6H 2 


598.1 


" anhydrous 


Fe 8 (QH 5 7 ) 2 


490 


Bismuth 


Bi C 6 H 5 7 


398 



939. Phenolsulphonates are salts containing the complex 
radical C 6 H 5 SO, [Ortho-sulphonic acid is C 6 H 4 .OH.HS0 3 .] The 
phenolsulphonates used in medicine and pharmacy are com- 
monly called " sulphocarbolates." We have phenolsulphonates 
of— 

Sodium = NaC 6 H 5 SO t 2H 2 = 232 
Calcium = Ca (C 6 H 5 S0 4 ) s = 386 

Barium = Ba (C 6 H 5 SC) 4 ) 3 = 483 

Zinc = Zn (QHsSOO^^O = 555 

940. Salicylates contain the acid radical C7H 5 3 The 
salicylates used in medicine are all made from salicylic acid or 
from salicylate of sodium. Salicylic acid is made from phenol 
(commonly called "carbolic acid""). The volatile oil of winter- 
green contains 90 per cent, of methyl salicylate. The alkali 
salicylates are readily water-soluble, and salicylate of zinc 
moderately soluble, while salicylic acid is nearly insoluble. 

The common salicylates are: 

Salicylic Acid — H =138 

Sodium Salicylate = 2Na 0»H 2 = 338 

Lithium " = 2 LiC 7 H,0 3 H 2 = 306 

Zinc " = Zn H 5 3 ), 3 H 2 = 393 

Bismuth " = Bi(C 7 H 5 3 ) 3 = 620 



276 CHEMISTRY. 

941. Benzoates. — The acid-radical of the benzoates is 
C 7 H 5 2 . Benzoic acid occurs in benzoin, and is also produced 
synthetically from tolnol", etc. The benzoates of sodium, 
lithium and ammonium are used medicinally; they are all water- 
soluble and prepared from benzoic acid and the respective 
alkali carbonates. 

The formulas are : 

Benzoic acid HC 7 H 5 C = 122. 

Potassium Benzoate KC 7 H 5 2 = 160. 

Sodium " NaQH 5 ? H 2 = 162. 

Lithium " LiC 7 H 5 3 = 128. 

Ammonium " NH 4 C 7 H 6 2 = 139. 

Calcium " Ca(C 7 H 5 2 ) 2 = 282. 

Ferric " Fe 2 (C 7 H 5 2 ) 6 = 838. 



CHAPTER LIV 



HYDROCARBONS. 



942. Hydrocarbons. — The hydrocarbons are compounds 
of only the two elements, carbon and hydrogen. Hundreds of 
them are already known, and numerous others are possible. 

The hydrocarbon molecules may contain any number of carbon atoms, 
from one up to at least thirty-five. In all hydrocarbons containing more 
than one carbon atom, all the carbon atoms present are, of course, united by 
a portion of their bonds into a continuous chain or ring, or cluster, while all 
of the hydrogen atoms are united to the remaining carbon bonds. 

943. As carbon is a tetrad it follows that the highest propor- 
tion of hydrogen that can unite with carbon is present in the 
compound CH 4 , called methane (commonly called " marsh- 
gas"). 

944. All hydrocarbons may be arranged into several differ- 
ent series, each series represented by one general formula, and 



CHEMISTRY. 277 

the several members of each series differing from each other by 
the group CH 2 or a multiple of it. 

Such series are called homologous series. 

945. The first series, or methane series, of hydrocarbons 
begins with the following members: 

H 

I 

1 . H— C— H 

k 

H H 

I I 

2. H— C — C— H 

I I 
H H 

H H H 

I I I 

3. H— C — C — C— H . 

I I i 
H H H 

H H H H 

I I I I 

4. H— C— C — C — C— H 

I I I I 
H H H H 

H H H H H 

I I I I I 

5. H— C— C— C— C — C— H 

I I I I I 
H H H H H 

H H H H H H 

I I I .1 I I 

6. H-C— C — C— C— C— C— H 

I I I I I I 
H H H H H H 

It will be seen that for every additional carbon atom there must be two 
additional hydrogen atoms. This explains why it is that each member of the 
series differs from the preceding member by CH 2 . 

946. If you examine the formulas just presented you will find that this 
whole series may well be represented by the general formula: H(CH 2 )«H, for 



278 



CHEMISTRY. 



every member of the series consists of any number of groups of CH 2 linked 
together by their carbon bonds and the chain united to a hydrogen atom at 
each end. As commonly written the formulas are: 



CH 4 C 2 H 6 C 3 H 8 C 4 H 10 



and so on. 



In another series the first number is: 



II 



H 



H 

I 
= C 

I 
H 



the second member H — C — C=C 

I I I 
H H H 

H H H 

I I I 

and the third member H — C — C — C=C 

I I I I 
H H H H 

For this the general formkila (CH 2 )« might be assigned. 
947. But the general formulas for the homologous series of hydrocar- 
bons are usually expressed as follows: 

Series 1. CnW 2 n + 2 Lowest member known, CH 4 

C 2 H 4 
Co Ho 



C 8 H 8 
C 8 H 6 
C 10 H 8 

C 14 H 12 
Cl4"l0 

Ci 7 H 14 

Cl6H\ 

C22H14 
^26"20 

In these general formulas the italic letter n means any number. Thus the 
general formula for Series I, written CnH 2 n + 2 means: any number of car- 
bon atoms united with twice the same number plus two of hydrogen atoms; 



2. 


CnH 2 n 




3. 


CnH 2 n- 


-2 


4. 


CnH 2 n- 


"4 


5. 


CnH 2 n- 


-6 


6. 


C«H 8 «- 


-8 


7- 


C«H 8 «- 


-10 


8. 


CnH 2 n- 


-12 


9- 


CnH 2 n- 


-14 


10. 


C«H 2 ;z- 


-16 


11. 


CnH. 2 n- 


-18 


12. 


CnH 2 n- 


-20 


13- 


CnH 2 n- 


-22 


14. 


CnH 2 n- 


-24 


15- 


CnH 2 n- 


-26 


16. 


CnH 2 n- 


-28 


17. 


C«H 2 «- 


-30 


18. 


CnH 2 n- 


-32 



CHEMISTRY. 279 

the general formula for Series 2, written C«H 2 « means: any number of car- 
bon atoms united to twice the same number of hydrogen atoms; the general 
formula for Series 3, written C«H 2 « — 2 means: any number of carbon atoms 
united to twice the same number less 2 of hydrogen atoms; etc. 

948. Knowing the number of carbon atoms in any member of any one 
of these series we can write its molecular formula in accordance with the gen- 
eral formula for its series; thus the member of Series 1 having 12 carbon 
atoms must be C 18 H 26 ; of Series 2 it would be C 12 H 24 ; of Series 3, C 12 H 22 ; 
of Series 4, C 12 H 20 ; of Series 5, 'C 12 H l8 ; of Series 9, C 12 H 10 ; of Series 14 
there could be no member with but twelve carbon atoms, and of Series 10 to 
13 none are known having twelve atoms of carbon. 

949. Hydrocarbons are generally gaseous when containing less than four 
atoms of carbon; liquid if containing more than four but less than twelve 
carbon atoms; solid 'if they contain a higher number of atoms of carbon. 

950. According to the properties of their derivatives, the hydrocarbons 
are divided into two series — the fatty series and the aromatic series. Fats or 
fixed oils belong to the derivatives of the fatty series of hydrocarbons, and 
the aromatic acids and other aromatic or odorous compounds are derivatives 
of the aromatic series. 

951. Marsh gas, CH 4 , is a colorless and tasteless gas, which is generated 
in swamps by the decay of organic matter ; it is the principal constituent of 
the so-called " natural gas," and in coal mines it exists as " fire-damp." 

952. Hydrocarbons occur in coal oils, paraffines, petrolatum, paraffin 
oil, illuminating gas, natural gas oil of turpentine, oil of lemon and many 
other volatile oils, etc. 

Among the common hydro-carbons are: 

Paraffin = C6H34. 

Benzin = C 5 Hi 2 and C 6 Hi 4 . 

Turpenes= (Ci Hifi)«. 

Benzene ■*- C 6 H 6 . 

953. Among the derivatives or substitution products of hydro-carbons 
are: 

Chloroform, CHC1 3 , which is tri-chlor-methane. 

Iodoform, CHI 3 , which is tri-iodo-methane. 

The haloids of the hydro-carbon radicals correspond to the chlorides, 
bromides, iodides and cyanides of the metals. Thus, trichlormethane may 
be regarded as formyl chloride, or the chloride of the radical CH. Haloids 
of methyl (CH 2 ), ethyl (C 3 H 5 ) and other positive organic compound radicals 
(263) are well-known. 

954. Hydrocarbon Radicals are groups of carbon and hydrogen atoms 
having free carbon bonds. 



280 CHEMISTRY. 

When a hydrogen atom is removed from a hydro-carbon molecule, the 
remainder constitutes a positive radical with one valence unit; for every addi- 
tional hydrogen atom removed another valence unit is added to the radical. 
Thus, if we take one hydrogen atom from CH 4 , we have the radical CH 3 left, 
which is univalent; the removal of two hydrogen atoms would leave the rad- 
ical CH 2 with two free bonds: and if still another hydrogen atom be removed, 
we get the trivalent radical CH. 

955. The hydrocarbons (942) may be regarded as the hydrides of the 
hydrocarbon radicals. Thus Methane, CH 4 , can be looked upon as the 
hydride of methyl. CH 3 H; ethane, C\H 6 . as ethyl hydride. C 2 H 5 H, etc. 

956. Hydrocarbon radicals, in fact, form the same classes of compounds 
as are formed by metals, namely, oxides, sulphides, chlorides, bromides, 
iodides, cyanides, bases and salts. Their oxides are called ethers, their 
hydrates are alcohols, and the salts they form with the acids are called ethe 
real salts. 



CHAPTER LV. 

OTHER IMPORTANT CLASSES OF ORGANIC COMPOUNDS. 

957. Alcohols. — The alcohols of organic chemistry cor- 
respond to the metallic hydrates of inorganic chemistry. They 
all contain hydroxyl, HO. which is united to the hydrocarbon 
radical just as the hydroxyl in a metallic hydrate or base is 
united to the metal. 

There are three classes of alcohols, namely, primary^ secondary 
and tertiary alcohols. 

958. Primary alcohols all have the general formula H(CH 2 )n 
OH: that is. they ail contain the two groups, CH 2 and OH. 

When oxidized the primary alcohols yield first aldehydes, 
and then acids, containing the same number of carbon atoms. 

959. Secondary alcohols all contain the two groups, CH 
and OH. 

When subjected to the action of oxidizing agents they form 
acetones: and, upon further oxidation, acids containing a smaller 
number of carbon atoms. 



CHEMISTRY. 281 

960. Tertiary alcohols all contain C.OH. 

When oxidized they form neither aldehydes nor acetones, 
but are directly converted into acids having a smaller number of 
carbon atoms. 

961. Any organic compound containing hydroxyl of which the hydrogen 
can be replaced by an acid-radical, is an alcohol. If this alcohol yields alde- 
hyde when oxidized, and then an acid, it is a primary alcohol; if its oxidation 
results in acetone and subsequently acid, it is a secondary alcohol; and if upon 
oxidation it splits up, yielding an acid without first forming an aldehyde or an 
acetone, it is a tertiary alcohol. 

962. The simplest primary alcohol is methyl alcohol, CH 3 
OH (commonly called wood alcohol, or wood spirit). If two 
of the hydrogen atoms of the group CH 3 in that alcohol be 
replaced by hydrocarbon radicals, the resulting products are 
secondary alcohols; if all three of the hydrogen atoms of the 
methyl group are replaced by hydrocarbon radicals, tertiary 
alcohols result. 

963. It will be seen that the characteristic alcohol groups 
differ from each other by one or two hydrogen atoms, since 

Primary alconols contain CH. 2 OH 
Secondary " " CH.OH 

Tertiary " il C.OH 

964. Alcohols containing but one hydroxyl group are sometimes called 
monatomic alcohols, while those containing two hydroxyl groups are called 
diatomic alcohols, and alcohols with three hydroxyl groups are called triatomic 
alcohols. A monatomic alcohol is, of course, the hydrate of a univalent hydro- 
carbon radical ; a diatomic alcohol is the hydrate of a bivalent hydrocarbon 
radical ; and trivalent hydrocarbon radicals must furnish triatomic alcohols 

965. Among the alcohols the following are familiar: 
Methyl alcohol, or wood spirit = CH 3 OH. 
Ethyl alcohol, or ordinary alcohol = C 2 H :) OH. 
Amyl alcohol, or fusel oil = CJI^OH. 
Phenyl alcohol, or "carbolic acid " = C H 5 OH. 
Glyceryl alcohol, or "glycerin" = QH 5 (OH) 3 . 

Ethyl alcohol is formed by the fermentation of glucose ( 1 102) : 
C 6 H 12 O c = 2C 2 H 5 OH + 2 C0 2 
Glucose Alcohol Carbon dioxide 



282 CHEMISTRY. 

966 Mercaptans are compounds analogous to the alcohols in general 
structure, but containing HS instead of HO. They are, then, hydrosulphides 
of hydrocarbon radicals. 

967. Aldehydes. — When primary alcohols are oxidized in 
a limited supply of oxygen they are transformed into aldehydes 
by the removal of hydrogen. The name is coined out of the 
words <z/cohol dehydrogenated. The hydrogen thus removed is 
oxidized to water. 

It was stated (958) that the characteristic group contained in primary 
alcohols is CH 2 .OH; when the alcohol is changed to an aldehyde, that group 
is converted into CO.H or == C — H, which is a univalent group. 

Common aldehyde is CH3CO.H. 

There are no aldehydes corresponding to the secondary and tertiary 
alcohols. 

968. Ketones or acetones are formed by the incomplete 
oxidation of secondary alcohols (959). 

Secondary alcohols contain the characteristic group CH.OH; 
this becomes CO when a ketone is formed. The group CO, 
carbonyl, is bivalent, and in the formation of ketones or acetones 
both of the free carbon bonds of the carbonyl unite with hydro- 
carbon radicals. The simplest ketone is CH 3 .CO.CH 3 . 

969. Organic Acids are formed by the complete oxidation 
of alcohols. They all contain hydroxyl and correspond in their 
general chemical properties to the inorganic hydroxyl acids. 
But all organic acids contain, besides hydroxyl, the group CO, 
called carbonyl. The two groups, CO and OH have been written 
together as C0 2 H, or CO. OH, and called by one name, carboxyl. 
The simplest organic acid known is H.CO.OH, which is called 
formic acid. The next member of the same series of acids is 
acetic acid = CH 3 .CO.OH. 

970. The general formula for the series of organic acids 
corresponding to the methane series of hydrocarbons and the 
primary alcohols of the hydrocarbon radicals of the same series,, 
is H(CH 2 ) n CO.OH. Thus we have: 

Formic Acid = HCO.OH 

Acetic Acid = HCH 2 . CO.OH 

Propionic Acid = H(CH 2 ) 2 .CO.OH 






CHEMISTRY. 283 

Butyric Acid = H(CH 2 ) 3 .CO.OH 

Valeric Acid — H (CH 2 ) 4 . CO. OH 

Myristic Acid = H(CH 2 ) 13 .CO.OH 

Palmitic Acid = H(CH 2 ) 15 .CO.OH 

Stearic Acid = H(CH 2 ) 17 .CO.OH 

The acids included in the preceding table are all monobasic 

acids. 

Lactic Acid, which belongs to a different series, monobasic 

and has the formula 

H.CH 2 .CH(OH).CO.OH., or 

H— CH 2 

I 
HO— CH or HC 3 H 5 3 

I 
CO 

I 

OH 
Oleic Acid is HC 1S H 33 2 
Salicylic Acid is HC 7 H 5 3 
Benozic Acid is HC 7 H 5 2 
Gallic Acid is HC 7 H 5 5 

971. Among the bibasic organic acids are: 

Oxalic Acid, 

HO. OC. CO. OH., or 

OH 

I 
CO or (CO.OH)2 

I 
CO or H2C2O4 

I 
OH 

Tartaric Acid is: 

OH 

I 

CO 

! 

HO— CH or H 2 C 4 H 4 6 

I 
HO— CH or (CH.OH) 2 (CO.OH) 2 

CO or (CH.OH.CO.OH) 2 

! 

OH 



284 CHEMISTRY. 

Succinic Acid is: 

OH 

I 
CO 

I 

CH 2 or H 2 C 4 H 4 04 

CH 2 or (CH 2 ) 2 (CO.OH) 2 

I 

CO or (CHo.CO.OH), 

I 
OH 

972. Among the tribasic acids are: 
Citric Acid, 

OH 

I 
CO 



I or (CH,),.C.OH.(CO.OH) 3 , 

HO— C CO or H3C;H50 7 . 

I I 

CH 2 OH 

I 
CO 

I 

OH 



Malic Acid, 

O— H 

I 
CO 

HO— CH or CHo.CHOH.(CO.OH) 8 , 

I orH 3 C 4 H 3 05. 

CH 

I 
CO 

I 
OH 

973. Ethers. — The oxides of hydrocarbon radicals (or 
" hydrocarbon residues") are called ethers, or "simple ethers." 
The most common simple ethers are ethyl oxide, which is the 
ether of the Pharmacopoeia, and methyl oxide: 



CHEMISTRY. 285 

CH 3 v C 2 H 5 v 

O and O, or 

(CH 3 ) 2 and (C 3 H 5 ) 2 

Methyl ether Ethyl ether. 

974. Ethereal Salts, or Compound Ethers. — These are the 
salts formed by the positive hydrocarbon radicals with the 
inorganic and organic acid radicals. These ether salts are also 
called esthers. 

They are formed when acids and organic hydroxides (alcohols 
act upon each other, just as metallic salts are formed when acids 
and metallic bases act upon each other. 

Thus we have among the most common ethereal salts the fats or fixed 
oils, composed mainly of the oleate, palmitate and stearate of glyceryl; the 
delicious flavors of certain fruits are also compound ethers (amyl acetate has 
the flavor of pears; the flavor of apples is due to amyl valerate; pine-apple 
flavor is chiefly due to ethyl butyrate, and combinations of the acetates, valer" 
ates and butyrates of ethyl and amyl produce flavors resembling those of 
many fruits), and the pharmacopoeia contains preparations of the nitrates of 
amyl and ethyl, and acetate of ethyl, while oil of wintergreen is salicylate of 
methyl. 

Methyl acetate is CH 3 C 2 H 3 3 Ethyl acid sulphate is C 2 H 5 .HS0 4 

Methyl salicylate is CH 3 .C 7 H 5 3 Ethyl acetate is C 2 H 6 .C 2 H 3 O a 

Ethyl nitrite is C 2 H 5 .N0 2 Ethyl benzoate is C 2 Hs.C 7 H 5 2 

Ethyl nitrate is C 2 H 5 N0 3 Amyl nitrite is C 5 H n .N0 2 

Glyceryl oleate (olive oil) is C 3 H5.Ci t H3 3 2 

975. Recapitulation. — The constitution of the hydrocarbon radicals of 
the methyl series and their compounds may be shown by the following gen- 
eral formulas: 

Radicals of the methyl series = H(CH 2 ) U 

Hydrocarbons of the methane series = H(CH 2 ) n H 



H(CH 2 )n 



\ 



Oxides or simple ethers = -< ,0 

H(CH 2 ) n X 

Chlorides =H(CH 2 ) n Cl 

Bromides =H(CH 2 ) n Br 

Iodides = H(CH a )nI 

Alcohols, or hydrates = H(CH 2 )OH 

Aldehydes = H(CH 8 ) n CO H 

Ketones, or acetones = H(CH 2 ) n .CO.(CH 2 ) n H 

Ethereal salts = H(CH 2 ) n .CO.OH(CH 8 ) n 



286 





CHEMISTRY. 




Radicals. 




HCH 2 = Methyl 




H(CH 2 ) 2 = Ethyl 




H(CH 2 >3 = Propyl 




H(CH 2 ) 4 = Butyl 




H(CH 2 ) 5 = Amyl 




H(CH 2 ) 6 = Hexyl 




etc. 


Hydrocarbons: — 





Ethers. 



Alcohols: — 



Aldehydes. 



HCH 2 H = Methane 
H(CH 2 ) 2 H = Ethane 
H(CH 2 ) 3 H = Propane 
H(CH 2 ) 4 H = Butane 
H(CH 2 ) 5 H = Pentane 
H(CH 3 ) 6 H = Hexane 
etc. 



HCE 



= Methyl Oxide 



HCH 2 / 

H(8HU0°= PrOpylOxide 
]^H 2 ) 4 \ 0== Butyl Oxide 

SinS 3 wO= Pentyl Oxide 
etc. 



HCH 2 OH = Methyl alcohol 
H(CH 2 ) 2 OH = Ethyl alcohol 
H(CH 2 ) 3 OH = Propyl alcohol 
H(CH 2 ) 4 OH = Butyl alcohol 
H(CH 2 ) 5 OH = Amyl alcohol 
etc. 

H.CO.H = Formic aldehyde 

H.CH 2 .CO.H = Common aldehyde 



CHEMISTRY. 



287 



Acetones:^ 



Acids: — 



H.(CH 2 ) 2 .CO.H = Propyl aldehyde 
H.(CH 2 ) 3 .CO.H. = Butyl aldehyde 
H.(CH 2 ) 4 .CO.H. = Amyl aldehyde 
etc. 

H.CO.CH 2 .H 
H.CH 2 .CO.CH 2 H. 
H.(CH 2 ) 2 .CO.CH 2 .H. 
H.(CH 2 ) 3 .CO.CH 2 .H. 

or — 

HCH 2 

HCH/ 
H(CH 2 ) 2 - 

H(CH a ) r 

H(CH 2 ) 3 \ rn 

H(CH 2 ) 3 / LU ' 



CO 
CO 



H.CO.OH. = Formic acid 

H.CH 2 .CO.OH = Acetic acid 
H(CH 2 ) 2 .CO.OH = Propionic acid 
H(CH 2 ),CO.OH = Butyric acid 
H^CH^.CO.OH = Valeric acid 
etc. 
976. Carbohydrates are compounds containing carbon, 
hydrogen and oxygen, and no other elements, the carbon atoms 
being six in number or a multiple of six, while the hydrogen 
atoms present are twice as many as the oxygen atoms present. 
The word "carbohydrate" is based upon the general constitution just 
described, which suggested to the originator of the term carbohydrate that 
these substances might be likened to hydrates of carbon. The formula 
C 6 Hi O 5 looks like six atoms of carbon and five molecules of water, C^H^On 
looks like twelve carbon atoms and eleven molecules of water, and hydrates 
were formerly considered as compounds containing water. But the hydro- 
gen and oxygen in carbohydrates are not combined into water molecules, nor 
can carbon combine with water, so that the name is confusing. 



28S 



CHEMISTRY 



The principal classes of carbohydrates are as follows : 

Cellulose Group Saccharose Group Glucose Group 

(C 6 H 10 O 5 ) n Ci.3H2.2On C 6 H 12 6 

Cellulose Cane Sugar Grape Sugar 

Starch Milk Sugar Fruit Sugar 

Dextrin Maltose 

Gums Melitose 

977- Glucosides are complex bodies, sometimes having 
weak acid properties, sometimes neutral, which are split up 
under the influence of dilute acids, ferments, etc., especially 
with the aid of heat, yielding, as one of the decomposition 
products, sugar of the glucose group. 

Many of the neutral principles of plants are glucosides. 
Salicin, santonin, and amygdalin are examples of glucosides. 
978. Alkaloids are organic compounds resembling am- 
monia in that they contain nitrogen, have an alkaline reaction 
on test-paper, and are capable of neutralizing acids with which 
they combine to form salts. The chemical structure of alkaloids 
is not yet clearly understood. 

Alkaloids occur in many plants of decided medicinal potency. Most of 
them are so powerful in their effects upon the animal organism as to be 
poisonous, but some of the alkaloids appear to be simply bitter tonics. 

Among the common alkaloids are quinine, morphine, strychnine, 
veratrine, atropine, eodeine, caffeine, cocaine. 

By far the greater number of the alkaloids are solids, inodor- 
ous, bitter or acrid, non-volatile, and contain in their molecule 
carbon, hydrogen and oxygen as well as nitrogen. These are 
called amides, or quaternary alkaloids. 

Other alkaloids contain only carbon, nydrogen and nitrogen, 
these are called amines, or ternary alkaloids, and are liquid, vola- 
tile, and strongly odorous. The only common volatile alkaloids 
are nicotine, which is contained in tobacco; coniine, in conium ; 
and lobeline, in lobelia. 

When alkaloids combine with acids to form salts they behave 
exactly as ammonia does in that they unite with the whole acid- 
molecule, including its hydrogen, thus : 



CHEMISTRY. 289 

NH 3 + HNO3 = NH 4 N0 3 

Ammonia, Nitric Acid, Ammonium Nitrate, 

NH 3 + HC1 = NH 4 C1 

Ammonia, Hydrochloric Acid, Ammonium Chloride, 

NH 2 CH 3 + " HNO3 = NH 2 CH 3 HN0 3 

Methylamine, Nitric Acid, Methylamine Nitrate, 

2 C 21 H 22 N 2 2 4- H 2 SO, = (C 21 H 22 N 2 2 ) 2 H 2 S0 4 

Strychnine, Sulphuric Acid, Strychnine Sulphate, 

C 20 H 24 N 2 O 2 + HC1 = C 20 H 24 N 2 O 2 HCl 

Quinine, Hydrochloric Acid, Quinine Hydrochlorate. 



CHAPTER LVI. 



CHEMICAL NOMENCLATURE. 

979. The names of chemical compounds are generally con- 
structed out of the names of the constituent radicals so far as 
practicable. When, however, the molecule is complex and sev- 
eral different molecules contain the same elements that plan is 
impracticable, and the technical names given to such com- 
pounds are based upon their internal structure, source, or prop- 
erties, or upon other facts or conditions. Some names in com- 
mon use are entirely arbitrary and unscientific, and have mostly 
been transmitted from early times. 

The technical names of chemicals usually consist of two 
parts. 

980. Whenever the name of a chemical compound is 
derived from the radicals which enter into it, then the first part 
of the name is derived from or consists of the name of the posi- 
tive radical, while the second part is derived from the negative 
radical. * 

Thus we say silver oxide, potassium chloride, mercuric iodide, 
sulphur dioxide, calcium sulphide, copper nitrate, ethyl nitrite, 
magnesium sulphate, magnesium sulphite, etc. 



290 CHEMISTRY. 

981. Binary compounds (844) and many other compounds 
consisting of two radicals directly united have generic names 
ending with -ide and derived from their respective negative 
radicals. 

Thus compounds consisting of positive radicals (elemental or compound) 
directly united to oxygen are called oxides; when the positive radical is united 
to sulphur the compound is called a sulphide, etc. If we designate the posi- 
tive radical by the letter -t- 

R, then 

+ 4- 

RO=oxide. RH^hydride. 

+ + 

RS=sulphide. RP=phosphide. 

+ + 

RCl=chloride. RSe=selenide. 

RI=iodide. RCH 3 =methylide. 

+ + 

RBr=bromide. RN=nitride, etc. 

RCN=cyanide. 

982. But it often happens that two or more different com- 
pounds are formed by the same two radicals. There are five 
different oxides of nitrogen ; five oxides of manganese ; four 
oxides of chlorine ; three sulphides of arsenic ; two chlorides 
of iron or of mercury, etc. 

[The fact that any two radicals may form more than one compound by 
combining in more than one proportion is explained on the assumption that 
many of the elements have a variable valence, as explained elsewhere. Some- 
times this assumption seems unnecessary, as in the case of the oxides of 
nitrogen and chlorine, which may be represented by chains : N — O — N, 
N— O— O— N, CI— O— CI, CI— O—O— O— CI. etc.; but in other cases no 
explanation seems possible except that afforded by the assumption of variable 
valence (617 to 619).] 

983. Different names must, of course, be given to these 
different compounds in order to distinguish them from each 
other. The simplest method, and, therefore, the best, is to pre- 
fix the Greek numerals to the second part of the name, to indi- 
cate the number of times the negative radical is multiplied. 






CHEMISTRY. 291 

The oxides of nitrogen all contain two atoms of nitrogen 
and 1, 2, 3, 4 or 5 atoms of oxygen. They are, accordingly, 
represented by the following names and formulas : 

Nitrogen monoxide, N 2 0. 

Nitrogen dioxide, N 2 2 . 

Nitrogen trioxide, N 2 3 . 

Nitrogen tetroxide, N^O^. 

Nitrogen pentoxide, N 2 5 . 
This system is very explicit, and might advantageously be 
employed to a greater extent than it is. 

984. In some cases, however, this method of numeral pre- 
fixes (983) in connection with the negative radicals is not appli- 
cable as, for instance, in compounds of mercury which contain 
the same number of atoms of the negative element but differ- 
ent numbers of atoms of the positive element. 

985. A still more explicit method is to prefix numerals to 
both of the radicals. Thus we might say di-nitrogen mon- 
oxide, di-nitrogen di-oxide, di-nitrogen tri-oxide, etc. But this 
would seem to be superfluous in the naming of the nitrogen 
oxides, because all of them contain two nitrogen atoms. 

986. In naming certain compounds of polyvalent radicals 
the use of numerals as prefixes is the most convenient as well as 
explicit method. Thus we would distinguish normal sodium 
phosphate Xa 3 P0 4 , from Na 2 HP0 4 and NaH 2 P0 4 as follows: 
r\a 3 PO i = tri-sodium phosphate, or normal sodium phosphate. 
r\ T a 2 HPO i = di-sodium hydrogen phosphate. 

NaHoPOi = sodium di-hydrogen phosphate. 

In a similar manner we might call water di-hydrogen monoxide, and the 
so-called peroxide of hydrogen. H 2 2 , might be called di-hydrogen dioxide. 

NH 2 CH 3 is mono-methyl amine; NH(CH 3 ) 2 is di-methyl amine; and 
N(CH 3 )3 is tri-methyl amine. 

In organic chemistry the use of numeral prefixes is invaluable, as may 
be seen in the following: 

Ethylene diamine = C 3 H 4 (NH 2 ) 3 

Diethylene diamine = X 3 (C 2 H 4 ) 2 H 3 
Triethylene diamine = N 2 (C 2 H 4 ) 3 
Diethylene triamine = N 3 (C 2 H 4 ) 3 H5 
Triethylene triamine = N 3 (C 2 H 4 ) 3 H 3 
Triethylene tetramine == N*(C 3 H 4 ) 3 H 8 



292 CHEMISTRY. 

987. The numeral prefixes of Greek origin are: 

mono-, or mon-, meaning one or single. 

di- or dis-, " two or twice. 

tri- or tris-, " three or thrice. 

tetra-, " four. 

penta-, " five. 

hex a-, " six. 

hepta-, " seven. 

octo-y " eight. 

ennea-, " nine. 

deka-, " ten » 

988. The numeral prefixes of latin origin are: 

ten-, or uni- = one or single 

duo-, or £z'-, or bis-, = two or twice 

ter-, or /n, = three or thrice 

quadri-, or quadra- = four 

quinque-, or quinqui = five 

sexa— or sexi— = six 

hepta-, = seven 

tfffo- = eight 

non-, or nona-, or noni- = nine 

dec a— or deci— = ten 

989. The oxides of chlorine might well be named in the 
same manner as the oxides of nitrogen, but they are usually- 
named as follows: 

Hyp ochlor ous oxide C1 2 

Chlon?&.? Oxide C1 2 3 

ChlonV Oxide C1 2 5 

Perchloric Oxide O2O7 

These names show the use of two terminal syllables, -ous and 
-ic, which are very frequently employed, and nearly always used 
when only two compounds containing the same elements are to 
be distinguished from each other. There are also two prefixes, 
hypo- and per-, in the foregoing names of the oxides of chlorine. 
These and some other prefixes commonly employed in chemical 
nomenclature will now be explained together with the meaning 
of the terminations -ic and -ous. 

990. The endings, -ic and -ous, give an adjective form to 
the nouns to which they are affixed. Thus the noun argentum, 



CHEMISTRY. 293 

meaning silver, is turned into the adjectives argentic and argen- 
tous; the noun ferrum, meaning iron, is transformed into the 
adjectives ferric and ferrous; the word mercury into mercuric 
and mercurous; antimony into antimonic and antimonous; 
arsenic (or arsenum) into arsenic and arsenous; sulphur into 
sulphuric and sulphurous, etc. 

Lexicographically the adjectives argentous and argentic both mean sil- 
vern, mercuric and mercurous both mean mercurial, antimonic and antimon- 
ous both mean antimonial, arsenous and arsenic mean arsenical, and ferrous 
and ferric are adjectives which stand for and mean the same as the word 
iron in the expression iron mortar. But a Latin adjective with the termina- 
tion -ous differs in degree from one with the ending -ic. Thus argentous 
means more silvern than argentic; a ferrouscompound means one containing 
a greater proportion of iron than is contained in a ferric compound; mercur- 
ous chloride contains relatively more mercury than mercuric chloride does; 
arsenous oxide contains a greater percentage of arsenic, or, which is the 
same, a smaller percentage of oxygen, than the arsenic oxide contains; etc. 

Therefore, when any two compounds, both consisting of the 
same two radicals, are to be distinguished by different titles the 
one containing the greater proportion of the positive radical or 
lesser proportion of the negative radical is called an -ous com- 
pound; and the other, which contains the greater proportion of 
the negative radical, or the lesser proportion of the positive radi- 
cal, receives the name of an -ic compound. Of the two chlor- 
ides of iron the higher chloride, containing proportionately more 
chlorine, is called ferric chloride, while the lower chloride, con- 
taining less chlorine in proportion to iron than the other, is 
ferrous chloride. A higher oxide is an -ic oxide, and a lower oxide 
is an -ous oxide. 

991. The endings -ic and -ous are sufficient to distinguish 
two different compounds of the same two radicals, provided 
there are not more than two such compounds. As there are only 
two chlorides of iron, it is sufficient to call one the ferrous chlor- 
ide, and the other the ferric chloride. But when more than two 
different compounds are formed by the same two radicals, the 
terminations -ic and -ous are not only insufficient, but often mis- 
applied, or even confusing. 



294 CHEMISTRY. 

992. The additional prefixes, other than numerals, which 
have been employed in chemical nomenclature, are: 

Super- and hyper-, meaning above, over, in excess. 

per-, meaning thorough, to the full extent, through. 

sesqui-, half-as-much more, or one and one-half. 

sub- and hypo-, under or below. 

proto-, first or lower. 

multi-, ox poly-, many. 

ortho-, straight, regular, normal, original. 

meta-, beyond, after, derived from, deviating, altered, different. 

pyro-, as produced by fire or high heat. 

para-, beside, beyond, different, changed. 

Thus, super-oxide means a higher oxide; hyper-manganic acid or per- 
manganic acid means that acid of manganese which contains the greater pro- 
portion of oxygen; per-chloride of iron means the chloride of iron which con- 
tains the greatest possible proportion of chlorine with which iron can combine; 
sesqui-chloride of iron (which is the same as the per-chloride and ferric chloride) 
means a chloride of iron containing one and one-half times as much chlorine 
as the lower chloride contains; sub-chloride of mercury is the lower chloride 
of mercury, or calomel, or mercurous chloride, while per-chloride of mercury 
is the higher or mercuric chloride; hypochlorous oxide is a lower oxide than 
the chlorous oxide, and perchloric oxide is a higher oxide of chlorine than the 
chloric oxide, while chloric oxide is a higher oxide than chlorous oxide; ortho- 
phosphoric acid means the ordinary phosphoric acid, but meta-phosphoric 
acid is a different phosphoric acid derived from the ortho-phosphoric acid by 
the subtraction of one molecule of water (H3PO4 — H 2 0=HP0 3 ), and pyro- 
phosphates are formed when either meta-phosphates or orthophosphates are 
strongly heated; arabin is the acacia gum, but metarabin is a modified gum 
formed when acacia is subjected to heat; aldehyde has the formula C 2 H 4 0, 
and paraldehyde which has different properties is (C 2 H 4 0) 3 , but the difference 
between them arises from the internal structure. 

993. Nomenclature of Acids. — Whenever any element 
forms more than one acid-forming oxide, and accordingly has 
more than one acid, the different acids are distinguished from 
ach other by names analogous to those given to the respective 
oxides. Thus, the acid formed by an -ous oxide is called an 
-ous acid; the acid formed by an -ic oxide is called an -ic acid; 
a hypo— ous oxide forms a hypo-ous acid, a per-ic oxide forms a 
per-ic acid, etc. 



CHEMISTRY 



; 95 



Hypochlorous oxide forms hypochlorous acid, chlorous oxide forms 
chlorous acid, chloric oxide forms chloric acid, perchloric oxide forms per- 
chloric acid, sulphurous oxide forms sulphurous acid, and sulphuric oxide 
forms sulphuric acid. 

994. Nomenclature of Salts. — The salts formed by -ic 
acids are named after the acid by changing the terminal sylla- 
ble of the adjective to -ate, which at the same time converts the 
adjective into a substantive noun. Thus nitric acid gives 
nitrates, sulphates are the salts of sulphur/V acid, carbonates 
are formed by carbomV acid, etc. 

Salts formed by -ous acids have names ending with -ite 
instead of -ate. Thus hypophosphor^/j- acid forms hypophos- 
phitcs, nitn^i- acid forms nitrites, sulphur^.*- acid sulphites, and 
hypochlorous acid Aypochlorites. 

995. Other characteristic terminal syllables.— The names given to 
compound radicals generally end in -yl, as methyl ethyl, butyl, amyl, bis- 
muthyl, nitrosyl, carbonyl, hydroxyl, phenyl, etc. 

Names of alcohols sometimes end with -ol, as in carbinol, phenol, cresol, 
thymol, etc. ; but the same ending is unfortunately also used in the names of 
other compounds, as in benzol, toluol, etc. 

Aldehydes and their derivatives are sometimes given names ending with 
-al, as in chloral. 

The terminal -ane appears in the names of hydrocarbons of the methane 
series, as in methane, ethane, propane, butane, pentane, hexane, heptane, 
octane, nonane, decane, etc. In the names of other hydrocarbons and their 
derivatives the terminal -ate is often used, as in benzene, toluene, xylene, 
naphthalene., anthracene, etc. 

In the names of alkaloids the ending -ine is used, as in strychnine, 
aconitine, belladonnine, hyoscyamine, emetine, etc. Simple derivatives of 
ammonia, not containing oxygen, have names ending with the word amine, as 
methyl-amine, ethyl-amine, propyl-amine, phenyl-amine, etc. 

Glucosides and other neutral principles have names ending with -in, as 
in salicin, populin, aloin, saponin, etc. 

Sugars receive technical names ending in -ose, as in sucrose or saccha- 
rose, glucose, laevulose, maltose, melitose, mannitose, etc. But other carbo- 
hydrates also have received similarly constructed names, as, for instance, 
cellulose, which is not a sugar, but is the matter of which cotton, linen, and the 
walls of vegetable cells consist. 



296 



CHEMISTRY 



CHAPTER LVII. 

LAWS GOVERNING THE DIRECTION AND COMPLETENESS OF CHEMICAL 

REACTIONS. 

996. The course or direction which a chemical reaction may 
take is governed by various forces, among which the most 
important are electro-chemical polarity, and the solubility or 
non-solubility and state of aggregation of one or more of the 
products. 

997. Malaguti's Law. — In double decompositions between 
substances in a state of solution ''the most energetic acid 
tends to combine with the most powerful base." We may put 
this law more comprehensively and correctly in the following 
form: 

All che?nical reactions tend to the utiion of the strongest positive 
with the strongest negative radical present. 

To illustrate its application we will enumerate a few of the 
most important positive and negative radicals, respectively, in 
the order of their electro-chemical energy or position, and use 
the compounds produced by these radicals to show r how the 
law operates. 



Positive radicals. 



Potassium 

Sodium 

Calcium 

Magnesium 

Iron 

Copper 

Mercury 

Hydrogen 



Negative radicals. 



K 


Sulphate radical 


so 4 


Na 


Nitrate 


X0 3 


Ca 


Chloride " 


CI 


Mg 


Bromide " 


Br 


Fe 


Iodide 


I 


Cu 


Tartrate 


C 4 H 4 € 


Hg 


Acetate 


C0H3O2 


H 


Carbonate " 


C0 3 



In the preceding table potassium is the most powerful of all 
the positive radicals enumerated, then sodium, next calcium, etc., 
dowm to hydrogen, which is a weaker electro-positive radical 
than any of the others. Of the negative radicals the sulphate 
radical is the strongest, and of the others included in this table, 



CHEMISTRY. 297 

the nitrate radical stands next to the sulphate radical, the chlo- 
rine, bromine, iodine, etc., down to the carbonate radical, which 
is the weakest of them all. 

Now, according to Malaguti's law, sulphuric acid (which is 
hydrogen sulphate, HaSOJ must decompose all nitrates, chlo- 
rides, bromides, iodides, tartrates, acetates, and carbonates. 
Nitric acid (which is hydrogen nitrate, HXO s ) must decompose 
all chlorides, bromides, iodides, tartrates, acetates, and carbon- 
ates. Hydrochloric acid (which is hydrogen chloride, HC1) 
must decompose all bromides, iodides, tartrates, acetates and 
carbonates, etc. Potassium must displace sodium, calcium, 
magnesium, iron, copper, mercury and hydrogen from their 
compounds. Iron must take the place of copper, and copper in 
turn can usurp the place of mercury. 

Potassium being a stronger positive radical than copper, and 
the acetate radical being a weaker negative radical than the 
nitrate radical, if we mix a solution of potassium acetate with 
a solution of copper nitrate, there must be a reaction, resulting in 
the formation of potassium nitrate and copper acetate, for the 
reaction tends to the union of the strongest positive radical 
(potassium) with the strongest negative radical (the nitrate 
radical). 

In the same way and for the same reason we would get the 
following reactions: 

2KNO s +MgS0 4 =4K 8 S0 4 +Mg(NO s ) a 

6KC 2 H 3 2 +Fe 2 Cl 6 = 6KCl+Fe 2 (C 2 H 3 2 ) c 

Ca(C 2 H 3 2 ) 2 +MgBr 2 = CaBr 2 +Mg(C 2 H 3 2 ) 2 

2KBr+FeS0 1 = K 2 SO.+ FeBr, 

Mg(C 2 H 3 2 ) 2 +Pb(N0 3 ) 2 = Pb(C 2 H 3 2 ) 2 +Mg(X0 3 ) 3 

Na 2 C0 3 +2HCl = 2NaCl+C0 2 + H 2 
Malaguti's law, as stated and illustrated above, holds good at 
ordinary temperatures if the products of the reaction are both 
soluble salts; but the reactions are not complete (998). 

998. Berthollet's investigations prove that the operation of 
Malaguti's law (997) is greatly modified by the relative masses 
of the factors of the reaction, and by the relative solubilities 



298 CHEMISTRY. 

of the possible products, and it has been observed that a 
reaction in accordance with Malaguti's law is never quite com- 
plete unless one of the products of the reaction is either a 
volatile or an insoluble compound (999). Thus, while, in obedi- 
ence to Malaguti's law, a solution of potassium chloride mixed 
with a solution of copper sulphate should produce potassium 
sulphate and copper chloride — 

CuSO,+ 2KCl = K 2 S0 4 +CuCl 2 
the resulting liquid will in reality contain all of the four salts 
named; a mixture made of sulphuric acid with a solution of 
sodium nitrate will contain sodium sulphate, sodium nitrate, sul- 
phuric acid, and nitric acid; and a mixture made of a solution 
of magnesium sulphate with a solution of potassium tartrate 
will contain potassium sulphate, magnesium sulphate, potassium 
tartrate and magnesium tartrate. 

These are the results obtained when the proportions of the 
compounds mixed are the proportions required by theory for 
complete double decomposition according to the equations 
representing the reactions which should ensue according to 
Malaguti's law. 

But although the reactions which take place in accordance 
with this law do not progress to completion, the tendency of the 
reaction is unmistakable, and it is simply obstructed by physical 
conditions. 

Reactions, incomplete though they be, may thus take place 
between salts in a state of solution without any outward sign 
if the factors and products of the reaction are colorless as well 
as soluble. 

999. Berthollet's Law of the Formation of Insoluble 

Compounds. — If any two of the radicals taking part in a chemical 
reactio?i between salts in solution would produce an insoluble compound 
if united to each other, then these radicals will unite. 

In other words, "when we cause two salts to react by means 
of a solvent, if, in the course of double decomposition, a new 
salt can be produced which is less soluble than those we have 
mixed, then that new and less soluble salt will be formed." 



CHEMISTRY. 299 

Or, whenever, in any double decomposition between compounds in 
solution, an insoluble product is possible, theti that insoluble product will 
inevitably be formed. 

This law is general in its operation ; it produces complete 
reactions in the direction which it indicates, and it nullifies 
Malaguti's law in all cases where the two laws are in opposition 
to each other. 

A knowledge of the relative solubilities of chemical com- 
pounds, therefore, enables us to predict with certainty the direc- 
tion of the reaction in all cases where the factors of the reaction 
furnish the radicals required for the formation of insoluble 
products, and it also enables us to devise methods for the prep- 
aration of numerous substances. 

Knowing that lead iodide is insoluble, we also know that it must be 
formed whenever a solution of any soluble lead salt is mixed with the solu- 
tion of any soluble iodide. Knowing that lead iodide is a yellow insoluble 
solid, we know that we can not mix a solution of lead acetate or lead nitrate 
with a solution of potassium iodide, sodium iodide, or of the iodide of either 
ammonium, calcium, magnesium, zinc, or iron, without getting a yellow pre- 
cipitate. 

A solution of any one of the soluble salts of any of the heavy metals can 
not be mixed with a solution of any soluble hydrate, or carbonate, or phos- 
phate, without producing a precipitate, for, as we know, the hydrates, carbon- 
ates and phosphates of the heavy metals are all insoluble. Salicylate of 
quinine being insoluble in water we know that it would be impossible to mix 
an aqueous solution of hydrochlorate of quinine with a solution of sodium 
salicylate without getting a precipitate of quinine salicylate; but if enough 
alcohol is present, in which the quinine salicylate is soluble, no precipitate of 
that compound will be obtained, although quinine salicylate is of course 
formed in accordance with Malaguti's law, but we might expect instead (if 
enough alcohol is present) a precipitate of sodium chloride, which, although 
soluble in water, is not soluble in a liquid containing a considerable amount 
of alcohol. 

Most of the chemical incompatibilities met with in making extempora- 
neous liquid preparations arise from the formation of insoluble compounds. 
Hence the great importance of knowing the relative solubilities of chemicals. 

Common water, containing carbonates, chlorides, and sulphates, will not 
make clear solutions of the water-soluble salts of silver, lead, mercury, etc., 
because the carbonates, chlorides or sulphates of these and some other metals 
and bases are insoluble. 



300 CHEMISTRY. 

iooo. Berthollet's law of the formation of volatile 
products. — When dry heat is applied to a mixture of two 
compounds, if any volatile product can be formed by double 
decomposition, then that volatile product will be formed. 

Thus when ammonium chloride and calcium oxide are heated together, 
the products calcium chloride, ammonia and water are formed; when a mix- 
ture of mercuric sulphate and sodium chloride is heated, mercuric chloride 
sublimes and sodium sulphate remains. 

It may be said in addition that compounds which may be split up into two 
or more other compounds, of which one is volatile, are comparatively unstable 
and may be decomposed either by heat alone, or by double decomposition 
aided by heat, or even by double decomposition without the aid of heat. In 
-other words, simple decomposition or double decomposition takes place, 
as a rule, more readily when one or more of the products of the reaction are 
volatile than when no volatile products are formed. 

Thus carbonates are comparatively unstable; they are easily decomposed 
by even weak acids, find are split up by high heat. 

The student should here refer again to the action of heat upon salts (533). 

1001. Whenever a chemical reaction ensues in accordance 
w T ith the law of Malaguti (997), it progresses to completion pro- 
vided one of the two products is gaseous, as in the decomposi- 
tion of carbonates, sulphites, etc., by stronger acids. 

1002. It will now be readily understood by the student that 
the synthetical and analytical reactions applied in the produc- 
tion of chemical compounds and in analytical work are based 
chiefly upon the laws of Malaguti and Berthollet which have 
just been presented and to which indirect reference has been 
made also in the preceding pages. 



CHEMISTRY. 3OI 

CHAPTER LVIII. 

OXIDATION AND REDUCTION. 

1003. Oxidation. — To induce any metal or other element, 
or any compound, to take up or unite with oxygen is to oxidize 
that element or compound. 

Zinc oxide may be made by heating the metal strongly 
in free access of air. Combustion in oxygen or air, whether 
slow or rapid, is oxidation. To cause a lower oxide to take 
up more oxygen so as to form a higher oxide and to con- 
vert an -oics acid into an -ic acid, or an -ous salt into an -ic salt 
must also be called oxidation. Thus when an arsenite is con- 
verted into an arsenate, a sulphite into a sulphate, or phosphorous 
acid into phosphoric acid, or nitrogen dioxide into nitrogen 
tetroxide, oxidation takes place. 

1004. But the direct union of oxygen with an element, or the addition 
of oxygen to any compound, or the introduction of oxygen into a molecule, 
is not the only methods of oxidation possible. 

The proportion of oxygen in a molecule may be indirectly increased by 
removing some other element. When alcohol, C 2 H 5 OH, is changed to alde- 
hyde, C2H4O, this change is really effected by oxidation because two atoms 
of the hydrogen of the alcohol are oxidized to water and thereby removed 
from the C 2 H 5 OH, leaving C 2 H 4 0, which at the same time contains a greater 
proportion of oxygen than is contained in the alcohol, for alcohol contains 
16 parts of oxygen in 30, while the aldehyde contains 16 parts in 28. 

1005. When the ferrous sulphate is converted into ferric- 
sulphate by means of nitric acid, it is the hydrogen of the sul- 
phuric and nitric acids used that is oxidized to water at the 
expense of the nitrate radical, thus: 

6FeS0 4 +3H 2 S0 4 +2HN0 3 = 3Fe 2 (S0 4 ) 3 +N 2 2 + 4 H 2 0, 
and when ferrous chloride is converted into ferric chloride with 
hydrochloric and nitric acids the hydrogen of the acids is oxidized 
to water, while the chlorine from the hydrochloric acid raises 
the ferrous chloride to ferric: 

6FeCl 8 +6HCl.+.2HN0 3 — 3Fe 2 Cl 6 +N 2 2 + 4 H 2 0. 
Both reactions are instances of oxidation. 
The following reaction is also an example of oxidation: 
As 2 3 -+-2NaN0 3 H-Na 2 C0 3 =Na,As 2 7 +N 2 3 +C0 2 . 



302 CHEMISTRY. 

Nitric acid is also decomposed by organic substances, the molecule oi 
nitric acid being split up into the two radicals, N0 2 and HO, of which it is 
composed, and the group NO a is thus made to en:er into the organic 
molecule, where it replaces one atom of hydrogen, this hydrogen uniting 
with the hydroxyl to form water, as when cotton is converted into gun-cotton: 
C 12 H 2 o0 10 +6HN0 3 — C 12 H 14 4 (O.N0 2 ) 6 +6H 2 0. 

1006. The oxidizing agents are either oxygen itself or 
some oxygen compound which readily gives up all or a portion 
of its oxygen, such as nitric acid and other nitrates, chromic 
anhydride, potassium permanganate, potassium chlorate, man- 
ganese dioxide, etc. 

1007. Chlorine and the other halogens may act as indirect oxidizing 
agents in organic chemistry by removing hydrogen from the organic com- 
pounds; or, still more indirectly, by first introducing chlorine in the place of 
the hydrogen of the molecule, and subsequent introduction of hydroxyl to take 
the place of the chlorine, which can be effected with some metallic hydrate. 

1008. Reduction is the opposite of oxidation. It is the 
removal of oxygen from a molecule, or the diminution of its 
proportion by the introduction of other elements into the same 
molecule, or the replacement of a portion or all of the oxygen 
by some other radical. 

The reduction of oxides to metals is sometimes easily 
accomplished by heat alone, as in the case of the oxides of silver, 
mercury and gold. 

1009. Reducing Agents are substances having a strong 
affinity for oxygen, either at ordinary temperatures or when 
■strongly heated with the oxygen compound. Carbon and 
hydrogen are often employed as reducing agents. 

Thus, iron ore is reduced to metallic iron by smelting it 
down in a furnace with charcoal, and " reduced iron " of the 
Pharmacopoeia is made by passing a current of hydrogen over 
oxide of iron heated to redness. 

Sulphurous acid and other sulphites are also sometimes used 
as effective reducing agents. 

Less effective reducing agents are glycerin, alcohol, sugar, 
tannin, and many other organic substances. 



CHEMISTRY. 



303 



CHAPTER LIX. 

NEUTRALIZATION. 

1010. Soluble normal salts are most frequently prepared by- 
neutralizing the proper acids by the proper bases, or by metals, 
oxides, or carbonates. Thus any soluble sulphate may be pro- 
duced by neutralizing sulphuric acid, any acetate by neutralizing 
acetic acid, etc., by the requisite metal, oxide, base or carbonate. 

1011. Test papers. — Litmus is a blue coloring matter 
made from certain lichens. Acids turn it red. Alkalies restore 
the blue color. 

When suitable unsized paper, like thin, white filter paper, is dipped in a 
weak solution of litmus and then dried it forms what is called "test paper." 
The solution of litmus used for this purpose is made with weak alcohol, and 
when used without the addition of acid it forms blue litmus paper, which is 
turned red by acids, by certain acid salts, and by some normal salts in which 
the acid radical is a powerful one while the positive radical is "comparatively 
weak. If the litmus tincture is treated with a little diluted hydrochloric acid 
so that its blue color is just changed to red, then paper dipped in this liquid 
and dried constitutes red litmus paper, which is turned blue by soluble bases 
and by some salts of strong bases with weak acids. 

The litmus solution or tincture may be made of one ounce powdered 
litmus to ten fluidounces diluted alcohol; macerate for a day, shaking occa- 
sionally, and then filter. 

1012. Whenever it is stated in the Parmacopceia or in any 
other book that any certain substance has "an acid reaction on 
test paper," or that it exhibits an acid reaction, the statement means 
that the substance turns blue litmus red; whenever a substance 
is said to give a?i alkaline reaction, this means that it turns red 
litmus blue; and when a liquid or substance has a neutral reaction 
it does not change either the blue or the red litmus paper. 

Remember that acids turn blue litmus red, that alkalies turn red litmus 
blue, and that neutral salts do not effect litmus paper at all. 

Certain other blue vegetable colors are affected by acids and alkalies in 
precisely the same way as litmus. 

1013. When a strong acid and a strong base neutralize 
each other the normal salt formed has a neutral reaction on test 
paper. 



304 CHEMISTRY. 

Thus, if you put 200 grains of diluted acetic acid in a beaker, or in a 
graduate, and then add ammonia water, a little at a time, until the liquid 
no longer turns blue litmus paper red, but not so long that the liquid will 
turn red litmus blue — in other words, until the reaction is neutral — 
you will find that you have used just 34 grains of water of ammonia ; the 
diluted acetic acid turns blue litmus paper red, and the ammonia water turns 
red litmus paper blue ; but if you mix exactly 200 grains of strictly pharma- 
copceial diluted acetic acid with exactly 34 grains of water of ammonia of 
precisely the strength prescribed by the Pharmacoposia, you will find that 
the resulting liquid has a neutral reaction. If, however, the acetic acid is too 
weak the reaction will be alkaline, and if the ammonia is too weak the reac- 
tion will be acid. 

In making the solution of acetate of ammonium according to the Phar- 
macopoeia, diluted acetic acid is neutralized with ammonium carbonate; that 
is, carbonate of ammonium is added, a little at a time, to the diluted acetic 
acid until the reaction of the solution is neutral to test paper, or litmus 
paper. 

1014. In testing liquids with litmus paper to ascertain their reaction, it 
is necessary that the coloring matter of the paper (the litmus) be soluble in 
or wetted by the liquid, for otherwise the color is not affected. Thus, to test 
strong ether, for instance, it is necessary to moisten the litmus paper with 
water before applying the ether to it. In testing solutions obtained by neu- 
tralizing acids with carbonates, it may be the case that the solution is charged 
with carbon dioxide (" carbonic acid") and will, therefore, give an acid reac- 
tion on test paper, even if the acid has been neutralized by the carbonate; 
if the liquid be heated sufficiently to expel the "carbonic acid gas," or car- 
bon dioxide, the reaction obtained will, however, be true and may be found to 
be neutral notwithstanding the fact that it was acid before the liquid was 
heated. 

1015. Some salts are always alkaline in reaction, although 
they are normal salts, and even salts of an acid constitution — 
that is, salts still containing replaceable positive hydrogen — 
may have a decidedly alkaline reaction, as, for instance, potas- 
sium bicarbonate (acid carbonate of potassium), which at once 
turns red litmus paper blue. But this is because the carbonate 
radical is a very weak negative radical, while potassium is the 
strongest positive radical. 

Several normal salts of iron, zinc, etc., with the stronger 
acids, have an acid reaction, and even the basic ferric sulphate 
gives an acid reaction. This is because the sulphate radical is a 



CHEMISTRY. 305 

very powerful negative radical, which the iron is not sufficiently 
strongly positive to neutralize it as to its effect on vegetable 
colors. 

It is, therefore, to be always borne in mind that a normal salt, which is 
often called a neutral salt, does not mean a salt with a neutral reaction on test 
paper, and that a salt having such a reaction is not necessarily a normal or 
neutral salt chemically. In other words neutrality to test paper and neutrality 
as to chemical structure or composition are two wholly different things. 

1016. Soluble salts can not advantageously be prepared by 
double decomposition except when the bye-product is insoluble, 
so that the reaction is complete. But they can be made from 
acids by neutralization or saturation. 

Sulphate of zinc can be made by dissolving zinc in diluted sulphuric acid 
all that is necessary in this case is to add enough zinc — a little more than the- 
acid can dissolve — and to let the acid act upon the metal until it will not dis 
solve any more of it. The zinc will continue to dissolve just as long as there 
is any acid left ; but when all the acid has been saturated, or turned into zinc 
sulphate, no more zinc can be dissolved, for zinc is insoluble in a solution of 
its own sulphate. Similar results are obtained in many other cases when 
metals are dissolved in acids ; but not in all, for sometimes basic salts are 
formed if the metal is used in excess. 

If, instead of zinc, we should add the oxide of zinc, or zinc hydrate, or 
zinc carbonate, to the diluted sulphuric acid, the final result would be the 
same — zinc sulphate is obtained in either case. 

If the proportions of acid and metal, oxide, hydrate, or carbonate are 
exactly those required by theory, according to the chemical reaction, a nor- 
mal salt will generally be obtained; or, if the metal, oxide, hydrate or car- 
bonate is insoluble in a solution of the normal salt formed with the acid used, 
an excess of either of them may be added to the acid with the assurance that 
a normal salt is formed, and the bye-products in these reactions are either 
gases which pass off or water which is unobjectionable. When one of the prod- 
ucts of a reaction is either a gas or water the reaction also progresses to com- 
pletion. When carbonates are dissolved in acids the gas CO s together with 
water are the bye-products (1026). 

1017. The proportions required by theory to an even neu- 
tralization or double decomposition are shown by the chemical 
equations which represent the reactions: 

Zn + H 2 SO, = ZnS0 4 + H 2 
65 98 161 2 



306 CHEMISTRY. 

Thus it requires 65 pounds of zinc and 98 pounds of sulphuric acid to 
make 161 pounds of zinc sulphate, and 2 pounds of hydrogen will be formed 
at the same time. As the hydrogen is a light gas insoluble in solution of 
sulphate of zinc, it easily passes off. But these proportions are theoretically 
right only in case the sulphuric acid is absolute (or <z//sulphuricacid, H 2 S0 4 ,or 
100 per cent, strength), which it never is. The sulphuric acid of the pharma- 
copoeia and of the market is generally of from 96 to 98 per cent, strength, or 
contains from 96 to 9S per cent. H 2 S0 4 . If it should contain 98 per cent. , then 
of course 100 pounds of it would be required for 65 pounds of zinc, for 100 
pounds of a sulphuric acid of 98 per cent, strength would of course be equal to 
98 pounds of H 2 SC) 4 . On the other hand, as the zinc ought to be used in 
excess, 98 pounds of ordinary sulphuric acid is sufficient for 65 pounds of 
zinc, and 100 pounds of ordinary sulphuric acid (equal to 98 pounds of H 2 S0 4 ) 
would require a little more than 65 pounds of zinc. Again — 
Zn + 2HCl = ZnCl 2 + H 2 
65 73 136 2 

This reaction indicates that 73 pounds of HC1 must be used for 65 
pounds of zinc to make 136 pounds of ZnCl 2 . It is, of course, 73 pounds 
of absolute HC1 and not 73 pounds of the hydrochloric acid as we find it in 
the market; the hydrochloric acid used contains only 31.9 per cent, of HC1, so 
that in order to get 73 pounds of HC1 we must tak*e 229 pounds of the ordi- 
nary acid. 






CHAPTER LX. 



PRECIPITATION. 

I0l8. Precipitation is the formation of insoluble solids in 
liquids. 

Precipitation can occur only in liquids, and the precipitate is 
always solid. 

Precipitation results when the dissolved matter is converted 
into insoluble matter, or when the solvent is changed so as to 
become a non-solvent. 

When the dissolved matter is changed that change is the 
result of chemical reaction. 

When the liquid in which the precipitation is caused to take 



CHEMISTRY. 307 

place becomes changed from a solvent to a non-solvent while 
the previously dissolved matter remains the same in kind, this 
change in the liquid is generally produced by the addition of a 
non-solvent miscible with the first liquid. 

Thus resins, camphor and other alcohol-soluble substances insoluble in 
water are precipitated from their alcoholic solutions on the addition of water, 
and gums, albumin, and other water-soluble substances insoluble in alcohol 
are precipitated from their water solutions by the addition of alcohol. 

1019. Precipitation resulting from a change in the liquid, by which it is 
rendered incapable of holding the dissolved matter any longer in solution, is 
sometimes called "physical precipitation" because it is a purely pbvsical 
phenomenon unaccompanied by any chemical change. The formation of new 
and insoluble solids in a liquid by chemical reactions is called " chemical pre- 
cipitation." 

1020 The separation of solid matter from a solution by a reduction of 
temperature, or by loss of a portion of the solvent from evaporation, is not 
precipitation. 

Nor is the separation of a liquid from its solution upon the addition of a 
non-solvent called precipitation, as for instance the separation of castor oil 
from its solution in alcohol by the addition of water. 

1021. Precipitation frequently takes place as the result of 
slow chemical reactions caused by the influence of changes of 
temperature, the action of light or of air, and other natural causes. 
But by far the most frequent cause of precipitation is the inten- 
tional mixing of two or more substances, generally in the form 
of solution for the purpose of producing certain products or for 
analytical purposes, and these intentional precipitations are the 
result of double chemical decomposition attended by the forma- 
tion of insoluble products. 

1022. A great number of chemical compounds are insoluble 
in water, and these compounds can, therefore, usually be pre- 
pared by double decomposition. 

Moreover, the value of many of the most important analyt- 
ical reagents depends upon precipitations caused by them. 

Precipitation is accordingly of very great importance in 
chemistry and pharmacy. 

But this chapter will be devoted wholly to the consideration 
of precipitation as a synthetical process. 



308 CHEMISTRY. 

1023. For the preparation of insoluble pharmaceutical chem- 
icals precipitation by double decomposition is found to be a 
more advantageous method in a great majority of instances 
than any other. 

1024. To produce precipitation by double decomposition 
there must be two factors of the reaction. One of these is called 
the precipitand and the other is the precipitant. 

The precipitand is alwaysa liquid. 

The vessel in which precipitation is to be performed is called 
the precipitating vessel. It may be a beaker, a wide-mouthed 
bottle, a stone jar, a barrel, or any other suitable vessel, according 
to the quantities operated upon and the nature of the materials. 

The precipitand is the liquid first put in the precipitating vessel; 
and the precipitant is the other factor of the reaction which 
must be added to the precipitand. 

It is obvious from the preceding statements that you can make either 
of the two substances used the precipitand or the precipitant at will. Which- 
ever solution you place in the precipitating vessel first is by reason- of that 
fact alone the precipitand, and the other must consequently be the precipitant 
and must be added to the precipitand. But we shall soon see that it makes a 
vital difference which of the two substances is used as a precipitand. 

The precipitant may be either a liquid, a solid, or a gas. 

1025. The best results are obtained when both the pre- 
cipitand and the precipitant are liquids. They are generally 
solutions of salts. Solutions which are to be used for the prep- 
aration of chemical products by precipitation must be perfectly 
clear; they are invariably to be filtered through good white filter 
paper, unless so corrosive as to disintegrate the paper; or, if 
they can not be filtered through paper, they must be allowed to 
stand long enough to become clear by the subsidence of any 
solid particles in them, or by filtration through asbestos or glass 
wool, or in some other effective manner. 

1026. When two solutions constitute the precipitand and 
precipitant, as is very generally the case, they must be mixed 
with each other in just the order and manner required by the 
circumstances of each case and the course of the ensuing reac- 
tion. When they have been properly mixed and the double 



CHEMISTRY. 



309 



decomposition completed, there are usually two products of the 
reaction contained in the precipitating vessel. One of these is 
the precipitate or insoluble solid, which is usually the principal 
product, and the other is the soluble matter held in solution in 
the liquid. 

The liquid in which the precipitate is formed is sometimes 
called the 7nother liquor, which term is also used to designate the 
liquid remaining after the deposition of crystals from a solution. 
The matter held in solution in the mother liquor is usually the 
secondary product, or byeproduct. It sometimes happens, however, 
that the soluble product is the principal product, and the pre- 
cipitate a bye-product. 

When the precipitate is heavy enough to descend to the bot- 
tom of the vessel, leaving the greater part of the liquid stand- 
ing over it and free from solid particles, then the mother liquor 
is frequently referred to as the supernatant liquid. 

1027. Proportions of the Factors of Reaction. — The 
relative quantities of the two factors of the reaction necessary to 
complete mutual decomposition are, of course, easily calculated 
from the molecular weights in accordance with the chemical 
equation representing the reaction. 

Thus, if we want to make mercuric iodide we must have a soluble mer- 
curic compound and a soluble iodide as our materials; we select mercuric 
chloride and potassium iodide as the most convenient and suitable. The 
reaction between them would be : 

HgCl 2 + 2KI — Hgl 2 + 2KCI. 
271 2X166 454 2X74-6. 

The molecular weight of mercuric chloride is 271 ; of potassium iodide, 
166 ; but two molecules of potassium iodide are necessary, as seen by the 
equation, so that 2X166 or 332 parts of it must be taken for 271 parts of mer- 
curic chloride; these materials will give as products 454 parts of mercuric 
iodide, and 2X74-6 or 149 parts of potassium chloride. To prove the cor- 
rectness of these quantities add together the numbers on each side : 

271 454 

and 
332 149 

603 603 



3IO CHEMISTRY. 

The sums are equal and, therefore, correct if the reaction is correctly rep- 
resented by the equation, as in this case it is, for you will find by the valences 
of the four radicals Hg, K, I and CI, and the fact that the same four elemen- 
tal radicals, and the same number of atoms of each of them, are to be found 
on both sides. 

1028. It is evident that if exactly 271 ounces of mercuric chloride and 
332 ounces of potassium iodide are used, and if the reaction between them 
is complete, so that every grain of each is decomposed, then we would ge< 
exactly 454 ounces of mercuric iodide and 149 ounces of potassium chloride. 

In some cases the exact proportions required by theory (according to 
the equation representing the reaction) are the proper proportions; but in by 
far the greater number of cases of double decomposition it is absolutely 
necessary to vary these proportions and to use an excess of the precipiiand 
(1024). 

The theoretical proportions will not do when it is necessary to insure 
complete decomposition of at least one of the factors of the reaction — the pre- 
cipitant; and this is generally necessary to insure a pure product. 

1029. As a rule that factor of the reaction which supplies 
the positive radical of the product must be completely decom- 
posed and must be used as the precipitant ; while the other 
factor, which furnishes the negative radical of the product must 
accordingly be used in excess of the amount required by theory, 
and must be the precipitand. In such a case, at the end of the 
reaction, all of the precipitant is completely decomposed, while 
a small quantity of the precipitand remains in the mother liquor 
together with the bye-product(io26). 

Any considerable deviation from the proportions required by 
theory would, however, involve unnecessary loss or waste, so 
that the excess used of the precipitand is to be moderate. 

In the production of mercuric iodide from mercuric chloride and potassium 
iodide (1027) the potassium iodide must be used in excess, and its solution 
must therefore be put in the precipitating jar first, because the mercuric 
chloride which furnishes the positive radical (Hg) of the product (Hgl 2 ) must 
be completely decomposed. 

1030. The Solutions employed in making chemical prod- 
ucts by precipitation must be of suitable degree of strength and 
temperature; and they must be mixed in the proper order, grad- 
ually and with brisk stirring. 



CHEMISTRY 



311 



Dilute and cold solutions generally tend to produce finely 
divided, light and bulky precipitates, while strong and hot solu- 
tions, as a rule, produce coarser and heavier precipitates. 

1031. Physical character of the precipitate. — This de- 
pends upon several conditions. Aside from the fact that each 
particular substance has a tendency toward a given form or 
physical condition, it is generally the case that this condition 
may be more or less modified by external influences, as has been 
indicated with regard to the degree of strength and tempera- 
ture of the solutions (1030). Instant precipitation usually 
results in a finely divided product, while a precipitate slowly 
formed may be coarser. 

When hot solutions are employed and the substance precipi- 
tated is not insoluble in hot water the precipitate will be dis- 
tinctly crystalline, whereas the same substance can be obtained 
in very fine powder when precipitated from cold liquids. 

Precipitates vary, then, in density, state of division, and form 
according to their chemical composition, and the conditions 
under which they were formed. 

They may be light or heavy, fine or coarse, amorphous or 
crystalline, gelatinous or curdy, pulverulent or stringy, etc. 

1032. The precipitate is frequently materially affected by 
continued contact with the mother liquor. Experience has 
demonstrated that in some cases it is necessary to allow the 
precipitate to remain in the liquid for a time before it is washed, 
while in other cases it is necessary to remove it from the liquor 
as soon as possible. The method of procedure must, therefore, 
be determined in each case according to the requirements. 

1033. As the precipitate is in contact with the second prod- 
uct in the liquid, it is not sufficient to simply collect and dry it, 
but it must be washed first. 

The washing and collection of precipitates in synthetical 
pharmaceutical processes may be accomplished in various 
ways. 

If the precipitate is heavy so as to sink to the bottom of the 
precipitating vessel, the washing may be effected by affusion and 



312 CHEMISTRY. 

decantation of water. After the precipitate has been formed and 
allowed to subside, the mother liquor may be decanted, or poured 
off, or it may be removed by means of a siphon. Then the pre- 
cipitating vessel is filled up with pure water, and the precipi- 
tate stirred up well with this water, after which subsidence is 
allowed to take place again, and as soon as the precipitate and 
the supernatant liquid, which now consists of wash water or 
washings, have separated the wash water is immediately again 
decanted and the vessel filled up with pure water. This alter- 
nate affusion and decantation of water is repeated several times, 
being continued until the washings no longer contain any solu- 
ble matter, which may be detected by the taste as long as the 
amount is considerable and by chemical tests when less. ' 

When the precipitate is very light and large quantities oper- 
ated upon, the washing may be effected by mixing the magma 
(a finely divided, bulky, light precipitate which does not readily 
separate from the liquid is called a " magma") with water in a 
suitable vessel, and then pouring the mixture upon a muslin 
strainer, so that the wash water may run off; then returning the 
magma to the vessel again to be mixed with a fresh portion of 
pure water and pouring the mixture again upon the strainer as 
before, repeating this as many times as may be necessary. 

Very small quantities of precipitates are best washed on a 
paper filter, the wash water being in this case poured over the 
precipitate in the filter and allowed to run through, after which 
more water is added, and the washing thus continued until the 
precipitate is freed from the soluble matter. 

The washing is sometimes effected with hot water, and in 
some cases with alcohol or other liquids, but water of common 
temperature is in most cases employed for this purpose. 

IO34. When the washing is completed, the wet precipitate 
is put on a paper filter or a muslin strainer, according to' quan- 
tity, and allowed to stand until drained free from the end wash- 
ings as far as practicable, after which the moist product is 
spread out on paper or muslin to dry. 

Sometimes the precipitate retains the water so tenaciously 



CHEMISTRY. 313 

that it is necessary to expedite the work by forcibly pressing 
the water out. The magma or other precipitate is for this pur- 
pose put in a press cloth or press bag and the water squeezed 
out of it by means of a screw press. 

In drying precipitates it is necessary to bear in mind that 
many substances are decomposed or altered by contact with 
the air or by the influence of light, and such precipitates as are 
liable to be injured in this way must be protected as far as 
possible. 

Sometimes the drying process may be hastened by the aid of 
heat; but in many cases the product is damaged by heat. 

1035. When the precipitate has been dried (it must be made 
perfectly dry) it is powdered and sifted through a fine sieve, 
unless already in uniformly fine powder. 



PART III 



ABOUT DRUGS. 



PART III. 



ABOUT DRUGS. 



CHAPTER LXI. 

INTRODUCTORY. 

1036. Medicines. — All substances used to relieve or remove 
pain or disease are called medicines. They include crude drugs, 
medicinal chemicals, and pharmaceutical preparations. 

1037. Crude Drugs are medicines consisting of natural or 
unprepared products derived from the mineral, vegetable and 
animal kingdoms, such as minerals, plants or parts of plants, 
exudations like gums, resins and oleoresins, and animals or 
animal substances like cantharides, castor, musk, etc. 

Many substances not in their natural state, but more or less 
prepared, are, however, also called crude drugs when common 
articles of commerce aside from their pharmaceutical and 
medicinal uses, or articles not prepared by pharmacists or 
chemists, as oils, etc. 

1038. Inorganic Drugs are those derived from the mineral 
kingdom, either in the natural state, or such as have passed 
through some process of manufacture or purification, but not 
yet in a condition suitable for medicinal applications: For Ex. — 
Native sulphide of antimony, lime, impure sulphates of iron, zinc, 
magnesium and copper, sugar of lead, litharge, common potash, 
borax, alum, soda, sulphur, commercial acids, etc. 

1039. Organic Drugs are crude drugs derived from the 

317 ~ 



318 ABOUT DRUGS. 

vegetable and animal worlds. The plant drugs are numerous, 
animal drugs few. 

1040. Vegetable Drugs are the most important of all 
drugs. 

There are thousands of plants which have been at one time 
or another used for medicinal purposes, and of these about six 
to eight hundred are still used sufficiently to be articles of 
commerce. 

In the Pharmacopoeias of the United States, Great Britain, 
Germany, France and Sweden there are very nearly 600 vege- 
table drugs, of which about 100 are official in all five, less than 
60 in four only, a little over 40 in three only, and less than 100 
in two pharmacopoeias only. But one-fifth of these drugs are 
not active medicinal substances being used only pharmaceutic- 
ally in preparations employed as vehicles for other and more 
active medicinal substances, or as flavoring agents, etc. 

1041. Plant drugs sometimes consist of the entire plant ; 
sometimes of several of its organs ; but generally of only one 
plant part, as the root, leaf, seed, bark, flowers, etc. Other 
vegetable drugs consist of starches, crude gums, resins, gum- 
resins, oleoresins, fixed oils, volatile oils, etc. 

1042. Animal Drug's were at one time more common than 
now. At present the only drugs of animal origin contained in 
the Pharmacopoeia of the United States are : Suet, wax, 
spermaceti, lard, lard oil, cod liver oil, pepsin, ox-gall, castor, 
musk, cantharides, cochineal, isinglass, and yolk of Qgg. 

1043. Chemicals are substances of definite chemical com- 
position, such as oxides, hydrates, acids, salts, chlorides, bro- 
mides, iodides, etc., prepared by chemical manufacturers or 
pharmaceutical chemists. 

The chemicals are, of course, grouped into two classes : 
inorganic chemicals derived from materials belonging to the 
mineral kingdom, and organic chemicals derived from plants or 
animals, or from hydrocarbons. 

1044. Pharmaceutical Chemistry is the chemistry of 
pharmacy. It includes not only the study of chemistry, in its 



ABOUT DRUGS. 319 

relations to the preparation, identification and examination of 
medicinal chemicals, both inorganic and organic, but also the 
study of the chemical constituents of the crude drugs, and the 
chemistry of "dispensing/' 

1045. Pharmaceutical Preparations are medicines pre- 
pared in convenient forms for direct administration or applica- 
tion, such as solutions, powders, pills, mixtures, syrups, tinct- 
ures, extracts, liniments, ointments, plasters, gargles, injections, 
suppositories, etc. 

1046. Galenical Preparations are pharmaceutical prepa- 
rations prepared by methods which do not include any chemical 
reactions or changes. 

When the constituents of the preparation are simply mixed, 
or when the active principles of a drug are extracted by means 
of simple solvents, the product is a Galenical preparation and 
the method of preparing it is a Galenical process. 

It is named so after Galen, a celebrated physician who lived 
in the second century and whose teachings were of the highest 
authority for about thirteen or fourteen centuries. Galen's 
medicines were, of course, limited to teas, decoctions, tinctures, 
vinegars, electuaries, and other preparations in no way dependent 
upon a knowledge of chemistry, a science which was unknown 
in Galen's time. 

When chemistry at last became an inportant power in the 
hands of the pharmacist there were warm controversies between 
the adherents of Galen and the disciples of Paracelsus, Valen- 
tine, and others who introduced chemicals into the Materia 
Medica. 

1047. Materia Medica is the Latin for medicinal substances, 
and as commonly used the term is synonomous with pharma- 
cology. In its more appropriate application materia medica 
means simply the materials from which medicines are prepared. 
In this sense the term has been used in pharmacopoeias and 
other books; thus the medicines were divided into two classes, 
one class comprising the " materia medica list," and the other 
the "preparations." 



320 ABOUT DRUGS. 

1048. For the purpose of classifying medicines by placing 
the crude drugs, or raw materials, in one group and the prepa- 
rations to be made from them into another, the expressions 
pha?-maca simplicia, " simple medicines," and pharmaca prceparanda y 
" medicines to be prepared," have also been used. 

1049. But a considerable number of pharmaceutical sub- 
stances or materials have no medicinal action, being used simply 
as diluents, solvents, vehicles, bases, excipients, flavoring or 
sweetening ingredients, etc. For the sake of convenience these 
are treated as if they were drugs, and the general term Materia 
Pharmaceutica is used to designate all substances used in the 
preparation of medicines whether these substances be medici- 
nally active or inert. 

Among the materia pharmaceutica not possessing medicinal 
activity are water, sugar, starch, lard, wax, glycerin, tragacanth, 
etc. 

1050. Pharmacology (from 4>a P/ ua/<ov, " medicine," and A6 V o S , 
"discourse") is that branch of the study of medicine which 
treats of the Materia Medica, and of the sources, commercial 
history, preparations, effects, uses and doses of medicinal 
substances. 

It enumerates the individual preparations or forms of admin- 
istration used or useful, but does not treat of the general princi- 
ples, processes and manipulations of pharmacy. 

1051. Pharmacognosy (from <j>d Pf xaKov y "medicine," and 
yvwou?, "knowledge") is that branch of the study of medicines 
which treats of the natural origin, appearance, structure and 
other means of identification of organic drugs. 

The study of pharmacognosy necessarily demands a fair 
knowledge of the organs, tissues, and microscopical structure 
of plants, and also a sufficient general knowledge of systematic 
botany. 

Botanical drugs are sometimes so nearly alike that it is 
necessary to resort to the microscope to remove doubt. 

1052. Identification of Medicinal Substances. — The 
ability to identify or recognize individual drugs, chemicals and 



ABOUT DRUGS. 32I 

pharmaceutical preparations is extremely valuable, since it is 
the means of detecting and preventing mistakes. Many of 
these substances may easily be recognized with the aid of the 
physical senses — sight, smell and taste. Familiarity with the 
more important drags, chemicals and pharmaceuticals that 
possess striking physical characteristics should, therefore, be 
cultivated. Crude drugs, especially, may often and with cer- 
tainty be recognized by the form, color, odor and taste. In other 
cases we may not be able to positively identify a drug by these 
physical properties, and yet when .a mistake has been made we 
may detect it by our ability to at least see that the article before 
us is not what it should be. But, although the external appear- 
ance and other physical properties of medicines should be famil- 
iar to us, and are the most valuable aids in detecting or avoiding 
errors, yet we must also make use of such other aids as we can 
render available for this purpose. 

A good knowledge of plant structure and plant organs, and 
ability to use the microscope, are necessary to proficiency in 
pharmacognosy. A knowledge of chemistry is requisite to 
identify chemical substances by appropriate qualitative tests ; 
and chemistry frequently aids us in identifying even Galenical 
preparations which are the most difficult of medicines to identify. 

Notwithstanding the difficulties, every good pharmacist 
should be able to identify such common preparations as the 
tinctures of opium, rhubarb, aloes or arnica; he should immedi- 
ately recognize the odors of jalap, ipecac, aloes or any other 
drugs which are equally characteristic in this respect. 

1053. Varieties of Drugs. — Of many crude drugs there 
are several varieties. Thus we have several varieties cf ginger, 
cinnamon, sarsaparilla, catechu, cinchona, senna, etc. It is 
important that in each such case the particular variety or varie- 
ties intended should be plainly specified or described. When- 
ever any two varieties of the same drug differ greatly from each 
other they are in fact to be distinguished from each other as if 
they were different drugs, which, in effect, they really are. 



322 ABOUT DRUGS. 

1054. Grades. — Each drug should be in good condition. 

If it consists of a plant part it should be gathered at the proper 
season and the right stage of development, it should be properl; 
cleaned and garbled; and carefully dried and preserved so as t< 
be perfectly sound. 

But climate, soil and season, together with various othei 
influences affect the quality of drugs to so great an extent that 
there are nearly always different grades of each drug. The 
elevation at which the plant grows may increase or diminish its 
medicinal value. Wild growing plants frequently differ from 
the cultivated as to their virtues. If to these causes of varia- 
tion be now added the ignorance, or carelessness, or accidents 
by which the drugs are gathered too early or two late, in 
unsuitable weather, from plants that are too young or too old, 
or from unsound plants, or are badly cleaned and dried, and il 
preserved, it is not a matter of surprise that there are widely 
differing grades of drugs. 

When several grades of the same drug are simultaneous!] 
found in the market the competent, conscientious and prudent 
pharmacist will, of course, select the best. Sometimes the 
differences are so great as to be self-evident. Thus no one can 
fail to observe the difference between dry, sound, well-preserved, 
bright flowers, and mouldy, discolored ones; between lean ergot 
grains scarcely half an inch long and plump ergot over an inch 
in length; between green, healthy-looking leaves and brown or 
3 r ellow, faded ones: between a sample having the proper strong 
characteristic odor of the drug, and one either having no odor 
at all or an odor not belonging to the sound drug; or between 
a drug full of inert stems, wood, sticks and stones, and another 
quite clean and free from all impurities or admixtures. 

But it happens most frequently that it requires special 
knowledge and training, such as only well educated and experi- 
enced pharmacists possess, to distinguish between good, bad 
and indifferent grades of the same drug. 

1055. As the vegetable drugs are not only the most numer- 



1 

it 



ABOUT DRUGS. 



323 



ous, but also the most important of the materia medica, a good 
knowledge of pharmaceutical botany is necessary to every intel- 
ligent pharmacist. 

Morphology (from m<>pH "form," and A6yo?, " discourse") treats 
of the organs of plants and their forms, transformations, and 
relations. The study of the conspicuous organs of plants (as 
root, leaf, flower, seed) as to their external conformation is 
also called organography. 

Ability to distinguish between roots and stems, leaves and 
flowers, fruits and seeds, etc., is acquired by the study of organ- 
ography, and is a necessary preparation for the systematic study 
of pharmacognosy (105 1). 

A fair knowledge of the minute details of plant structure, or 
of the tissues of plants and the cells of which these tissues are 
composed, is also necessary to the intelligent study and identi- 
Acation of drugs. - This is called vegetable histology, and some- 
times micro-botany. 

Finally, the acquisition of a sufficient knowledge of botany 
and pharmacognosy absolutely requires the use of scientific ter- 
minology and nomenclature. Technical ter?ninology is, indeed, 
necessary to satisfactory progress in any scientific study. By 
technical terminology is meant a system of precise words or 
terms, suitable for constructing brief accurate descriptions and 
for exact expressions and descriptions of facts, conditions and 
ideas. A good technical term or word expresses a great deal, 
and expresses it accurately. Some valuable technical terms are 
so expressive that in their absence it would require a great num- 
ber of words to express their meaning without ambiguity. 

A right study of science serves to teach the student to use 
his five senses with fidelity, and to report with accuracy what 
they perceive. He learns to see all that is to be seen, not with 
his imagination, but with his eyes ; and he learns also to state 
just what he sees — no more, and no less. But quickness and 
truthfulness of observation and reasoning must be followed by 
accurate expression, and hence science has formed for itself a 



324 ABOUT DRUGS. 

language by which knowledge maybe faithfully preserved, com- 
municated and increased. That language embraces technical 
terminology and nomenclature in its glossary. 

The term nomenclature is frequently used in the same sense as 
terminology, but nomenclature is a system of titles or names, 
only, whereas terminology embraces all other technical words as 
well as names. 

1056. Officinal drugs, chemicals, and pharmaceutical prep- 
arations are those commonly found in the "officine." 

By " officine 5 ' is meant the apothecary's shoD. 

Any medicinal substance or preparation usually kept in drug 
stores is, therefore, " officinal." 

Any drug or preparation maybe officinal whether official 
(1059) or not. 

1057. Magistral formulas and preparations are unofficial 
recipes and remedies prescribed by widely recognized high- 
medical authorities. 

1058. Extemporaneous preparations are those not kept 
in stock or " ready made " but always prepared for the occasion 
whenever required. They are, of course, such preparations as 
would deteriorate if kept on hand. 

1059. Official drugs, preparations and processes are those 
included in the national pharmacopoeias. But an official medi- 
cine is not necessarily an officinal one (1056). 

1060. Pharmacopoeias (from <t><x PfJ .a.Koi>, "medicine," and 
B-ocew, I "make") are books, compiled by governmental authority, 
or by authoritative national conventions, containing titles, 
definitions, descriptions, tests, formulas, and other informa- 
tion, directions and standards of quality, purity and strength 
for the medicines in common use. 

1061. The Pharmacopoeia of the United States is pre- 
pared and published by authority of the National Pharmacopoeia! 
Convention. This Convention consists of delegates appointed 
by the several incorporated medical and pharmaceutical colleges 
and societies of the United States, the American Medical Asso- 
ciation, the American Pharmaceutical Association, and by the 



ABOUT DRUGS. 325 

Surgeon Generals of the Army, the Navy and the Marine Hos- 
pital Service. The meetings of the Pharmacopceial conventions 
are held in Washington on or about the first day of May once 
in ten years. Pharmacopceial Conventions were thus held in 
1820, 1830, 1840, 1850, i860, 1870, 1880 and 1890. 

1062. The Authority of the Pharmacopoeia of the United 
States has been repeatedly sustained and enforced by Courts of 
Justice, by Congress in certain legislation, and by the Execu- 
tive Departments in official orders and regulations. 

1063. The Objects of the Pharmacopoeia are to estab- 
lish the identity of medicines, and to prescribe standards by 
which we may insure uniformity in the quality, strength and 
methods of *preparation of the officially recognized drugs, chem- 
icals and pharmaceuticals. 

Uniformity in the materia medica and pharmacy is of the 
highest importance, for without it there can be no science in 
therapeutics. 

The Pharmacopoeia provides titles, definitions, descriptions, 
identity tests, purity tests, working formulas, standards of 
strength, etc., for medicines commonly employed. 

1064. The Pharmacopoeia is the only national authority 
by which the quality, purity and strength of official medicines 
are governed. 

The several " dispensatories " and other compilations and 
commentaries are valuable according to their respective merits; 
but they are subordinate to the Pharmacopoeia in all matters 
touching the official standards. 

No physician and no pharmacist who has proper respect for 
his profession and its responsibilities can do without a copy of 
the Pharmacopoeia of the United States. Every physician 
should be acquainted with it; and every pharmacist should be 
familiar with all its details. 

1065. Pharmacy is the art of selecting and preparing 
medicines. Its importance is manifest and great. Without 
medicines the physician is powerless ; without the co-operation 



5-6 ABOUT DRUGS. 

of a competent pharmacist his course must be either the narrow- 
beaten path of mere routine, or doomed to disappointment and 
even dangers. 

An accomplished physician who has had time enough to 
become at the same time an accomplished pharmacist must be 
an extraordinary person, or must have very few patients and 
little else to attend to. 

An active physician finds it in every way disadvantageous to 
be his own dispenser. 

A good pharmacist must be able to identify medicines, must 
be a good judge of the quality of drugs and preparations, know 
how to test medicinal substances as to their purity and strength, 
to prepare them properly, and to combine and dispense them 
accurately, safely, and well. He must know enough about the 
drugs and their preparations to avoid incompatibilities., over- 
doses and all other dangers. 

The word si pharmacy'" is derived from the Greek word 
^p^toxo;-, which means medicine. 

1066. Pharmaco-Technology (from £a PM a*ov, "medicine," 
7c- v -, "art," and Ao'70?, "discourse,'') is a treatise on the art 
of pharmacy, or the principles, processes, and manipulations 
applicable in preparing, examining and dispensing medicines. 

1067. Dispensing Pharmacy is the art of combining and 
dispensing medicines. I: is the most important of all the 
responsible work which the pharmacist has to do. To be an 
ideal dispenser of physicians' prescriptions demands many 
qualifications. He must be familiar with the substances to be 
combined or dispensed and with their properties, their behavior 
toward each other, and their general effects upon man. He 
must be generally well informed, clear headed, wide awake, and 
careful. He must at all times be calm, courteous, and exhibit 
unfailing tact. He must be scrupulously neat, prompt, deft, 
accurate, and conscientious. 

1068. Pharmacodynamics (from >:-,:... "medicine," 



ABOUT DRUGS. 327 

and av'poptv, "power,") is that branch of pharmacology which 
treats of the quality, quantity and direction of the action or 
effects of medicines. 

1069. Therapeutics (from t^pa™™, to "cure") is that 
branch of the study of Medicine which treats of the effects and 
modes of action of medicinal agents, and their applications for 
the relief or cure of pain or disease. 

1070. Posology (from nwos, "how much," and Ad V o S "dis- 
course") is the consideration of the proper quantities or doses 
of medicines to be administered. 

A "posological table" is a tabular statement of doses. 

Doses are, of course, to a certain extent arbitrary. But they 
vary according to the age, sex, and condition of the patient and 
according to the effect it is intended to produce. 

A " medicinal dose " is a proper and safe dose; a " maximum 
single dose" is the largest dose of any particular medicine 
which it is considered proper and safe to administer; the " max- 
imum daily dose " is the largest total quantity of any medicine 
which it is proper or safe to administer in the course of a day 
or of twenty-four hours. A "toxic dose" is the quantity which 
when given at a single dose is liable to produce dangerous or 
injurious effects, or death. 

An "adult dose" is the full dose usually administered to a 
man of about 21 to 30 years. 

The "dose for children " is found by dividing the age (in 
years) of the child at its next birthday by 24 ; the fraction thus 
obtained is the proper fractional part of the adult dose that 
may properly be administered to the child. Thus, if the child's 
age at next birthday is 6 years, divide 6 by 24, which will give 
ft" or T At tne proper dose being, therefore, % of the dose for an 
adult (Dr. Cowling). 

1071. Human Physiology is the study of the functions 
of the organs of the human body. 

Anatomy is the study of the structure, organs and parts of 
the body. 

Every intelligent pharmacist should know what a stomach 



328 ABOUT DRUGS. 

is, or the liver, the heart, the blood vessels, muscles, bones, 
joints, etc. He should also have a fair knowledge of the ele- 
ments of human physiology, as of digestion, the blood, circula- 
tion, respiration, animal heat, the nervous system, etc. He 
should know something of hygiene, .food, ventilation, etc. 

He should certainly know what is meant b) r a tonic, cathar- 
tic, astringent, emetic, stimulant, sedative, diuretic and other 
common therapeutic terms. 

Finally, he should know what drugs are narcotic, the safe 
as well as toxic doses of poisonous substances ; what are the 
symptoms of poisoning by the common poisons, and the appro- 
priate antidotes that should be used in such cases in the absence 
of a physician. 

All of these things are taught in any good college of phar- 
macy. 

1072. Toxicology is the study of poisons and their effects 
and proper antidotes. 

Poisons are substances producing fatal or dangerous effects 
upon the organs of the body or their functions. 



CHAPTER LXII. 

THE COLLECTION OF PLANT DRUGS. 

1073. The medicinal value of plant drugs depends upon 
various conditions, as season, climate, soil, age, and develop- 
ment, whether the plant is wild-growing or cultivated, the part 
used, manner of collection, cleaning, pruning and garbling, cur- 
ing or drying, and preservation. 

1074. Plant drugs are generally sensitive to exposure, and 
by far the greater number deteriorate so rapidly, even when 
carefully kept, that a fre*sh supply must be procured annually. 
The new annual supply of each drug should, of course, be pro- 
cured at the season when it is in its best condition. There is a 



ABOUT DRUGS. 329 

proper annual season for gathering each plant drug, and it soon 
afterwards reaches the market through the drug brokers, and 
the new crop can then be obtained by the pharmacists, who ought 
to renew their stock of perishable drugs at that time. 

Some plant drugs can scarcely be preserved through one 
season without material deterioration; others are difficult to 
procure, of good quality, at any time, owing to the carelessness 
with which they are gathered, cured and shipped. Among the 
many perishable drugs are such important ones as ergot, dig- 
italis, erythroxylon, belladonna, pilocarpus, besides all herbs 
and flowers. 

1075. The time for gathering any plant drug is that season 
at which it contains the greatest proportion of its active prin- 
ciples. 

The plant part which constitutes the drug should be well 
developed and perfectly sound; it should neither be so young, 
immature and poorly developed as to be deficient in active con- 
stituents on that account, nor should it be so overgrown or old 
as to have begun to degenerate. 

In most cases it is safe to assume that a drug which has the 
fresh natural color belonging to it well preserved, and which 
possesses in a high degree and unaltered the peculiar odor and 
taste which characterize it, will prove to be of satisfactory 
medicinal quality. It is always true that when the drug is dis- 
colored, or its odor or taste impaired, it can not be of good 
quality. 

1076. In many plant drugs every part of the tissues is 
equally active ; in others again the softer, more friable portions 
are more active than the tougher tissues. 

Whenever the Pharmacopoeia defines a drug as consisting of 
any given plant organ or plant part, then no other portions of 
the plant must accompany the drug. Thus, when the bark of a 
root constitutes the drug, the whole root must not be used ; when 
the inner bark is the drug, it would not do to use both inner and 
outer bark together, nor to use the bark with pieces or shavings 



3$0 ABOUT DRUGS. 

of wood attached; when the leaves constitute the drug, the 
stems do not belong to it, too ; and when the drug consists of 
the seeds, only, the whole fruit must not be used. 

Again, when the drug is defined to be leaves of the second 
year's growth, this definition clearly excludes the leaves of the 
first year's growth as unequivocally as it excludes the root, or 
the leaves of an entirely different plant. 

I077. To illustrate the care with which the Pharmacopoeia 
defines plant drugs, we may quote a few official definitions : 

Anthemis consists of " the flower-heads of Anthemis nobilis 
collected from cultivated plants/' 

Conium is defined as " the full grown fruit of Coniujn macu- 
latum, gathered while yet green." 

Calendula is defined as "the fresh flowering herb of Calen- 
dula officinalis.''' 

Digitalis is "the leaves of Digitalis purpurea, collected from 
plants of the second year's growth." 

Eucalyptus is "the leaves of Eucalyptus globulus, collected 
from rather old trees." 

Frangllla is "the bark of Rhamnus Frangula, collected at 
least one year before being used." 

Juglans consists of " the inner bark of the root of Juglans 
cinerea, collected in autumn." 

We also find in the Pharmacopoeia such directions as the 
following : 

Belladonna Root, — " Roots which are tough and woody, 
breaking with a splintery fracture, should be rejected." 

Colchicum Root " which is very dark colored internally, or 
breaks with a horny fracture, should be rejected." 

Cubeb " should not be mixed with the nearly inodorous 
rachis or stalks." 

Ergot "should be preserved in a dry place, and should not 
be kept longer than a year." 

Galla. — " Light, spongy and whitish-colored Nutgalls should 
be rejected." 



ABOUT DRUGS. 331 

Prunus Virginia. — " The bark of the small branches is to 
be rejected." 

Senna. — "It should be freed from stalks, etc." 

1078. Roots and rhizomes are generally gathered in the 
autumn, from plants of two or three years' growth, when the 
plant has withered or the leaves fallen; or they are sometimes 
gathered in the spring before tne leaf buds expand. 

They must be freed from earth; best by washing them with 
water. 

If thick and succulent, they are cut or sliced, either trans- 
versely or longitudinally, before being dried. Thick, juicy 
roots must be rapidly dried at a sufficiently high temperature to 
prevent discoloration, mould or fermentation. 

Spongy, decayed, discolored or otherwise unsound portions 
must be rejected. 

Some roots of biennials are to be rejected if woody; but the 
roots of trees and shrubs are always woody. 

1079. Bulbs are sometimes preserved whole, as garlic and 
onions; but other bulbs are sliced and dried, as squill. Whole 
bulbs may be kept in nets or in dry sand. 

1080. Barks and woods are taken in the spring before 
the leaf buds expand. The bark from branches of two to four 
years' growth is generally better than younger or older bark. 

Sometimes the whole bark is used, because a separation is 
impracticable; but whenever a separation can be effected, the 
inner bark alone is used. The old, dry, dead, outer corky layer 
is always worthless. 

Barks are easily dried when well spread out over enough sur- 
face in an airy, shaded place at ordinary summer heat. 

1081. Herbs, leaves and flowers should be gathered in 
clear weather when the plants are dry and free from dew. 

Herbs must be fully grown, but gathered before flowering, 
or, if aromatic, immediately after the expansion of the flowers. 
Biennial herbs may generally be gathered at the end of the first 
summer, but sometimes (when narcotic) not until the second 
season. 



332 ABOUT DRUGS. 

The herbs are dried in bundles hung up on strings, or 
spread out in thin layers on paper or muslin in an airy, shaded 
place. 

Leaves are treated much like the herbs. If of narcotic 
plants those of the second year's growth are used. 

Flowers are extremely sensitive, and require to be dried 
with great care to preserve their natural colors. They are gath- 
ered as soon as expanded, spread out well on paper, and dried 
in an airy, shaded place at ordinary summer heat, being 
stirred or turned frequently until quite dry. 

1082. Fruits are gathered when fully ripe, except when 
succulent. Hard, dry fruits are easily sufficiently cured to 
insure their preservation. 

1083. Seeds must be fully developed when gathered, and 
are easily dried. Sometimes they are best preserved in their 
capsules. 

1084. When sufficiently dried the plant drugs should be put 
into suitable receptacles, such as tin cans, or tightly closed bot- 
tles, or well made drawers with snugly fitting covers. 

They must be protected against light, exposure to the air or 
to moisture, and against too high temperature. In other words, 
plant drugs must be kept in well closed receptacles in a moder- 
ately warm, shaded place. 



CHAPTER LXIII. 

THE CHEMICAL CONSTITUENTS OF PLANT DRUGS. 

1085. The proximate principles of plant drugs are the 
several kinds of chemical constituents naturally formed and 
contained in plants and separable from the plant parts as well 
as from each other by the aid of different solvents. 



ABOUT DRUGS. 333 

1086. The Classification of Plant Constituents.— The 

proximate principles of plant drugs may be grouped into a 
limited number of classes, as follows : 

1. Cellulin (or cellulose) and its modifications, as lignin 
etc. (1090). 

2. Starches, or amylaceous substances (1092). 

3. Gums, or vegetable mucilages (1093). 

4. Pectinous substances (1099). 

5. Sugars, or saccharine substances (1100). 

6. Albuminous substances, or vegetable albumin (1104). 

7. Fixed oils, or fats (1105). 

8. Organic acids (mi). 

9. Volatile oils (1112). 

10. Resins (1118). 

11. Neutral principles not belonging to any of these other 
classes (1125). 

12. Alkaloids (1128). 

1087. Of these twelve classes of proximate principles only 
cellulin (or cellulose) in its various forms is entirely insoluble in 
all the ordinary simple solvents, such as water, alcohol, ether,, 
benzin and chloroform. 

All the other classes of proximate principles are soluble in 
one or more of the solvents named, and can, therefore, be 
extracted from the drugs in which they are contained. 

1088. The Inert Constituents of Plants.— The sub- 
stances belonging to either of the first eight classes enumerated 
(1086) exhibit no decided medicinal action ; they are either 
absolutely inactive or have but a very mild effect. 

1089. The Active Principles of plants are either volatile 
oils, resins, neutral principles belonging to class n (1086), or 
alkaloids. 

Many plant drugs contain but one " active principle "; others 
two, or three, or more. In a drug containing several active 
constituents, all of them may belong to the same class of proxi- 
mate principles, or each may belong to a di# erent class. 



334 ABOUT DRUGS. 

1090. Cellulin and lignin. — The substance of which cell 
walls, cell membranes, and fibres are constructed is called cellu- 
lin or cellulose, and it occurs in various modifications and forms. 
Lignin is the altered cellulin which constitutes wood and woody 
Jibre. 

Plant drugs containing large quantities of woody fibre are 
called fibrous, and their powders are fibrous powders. 

Woody roots are tough because of the large proportion of 
lignin they contain. 

1091. As the other proximate constituents of plants are 
contained in the little closed sacs' or cells, which are made up 
of cellulose, or in the little spaces between those cells, or in 
canals, cavities or vessels bounded by cell walls or cellular 
tissues, it follows that whenever the extractable substances are to 
be removed from any drug consisting of plant organs, or when, 
its soluble matters are to be extracted, the solvent used must 
either be capable of passing through the vegetable membranes 
into the closed cells and other cavities, dissolving the substances 
contained within them, and then passing out again carrying 
with it the dissolved matters, or, if the solvent can not thus 
pass through the membranes, the drug must be disintegrated so 
that the solvent can come in direct contact with the proximate 
principles when the cells and intercellular spaces shall have 
been broken open. 

1092. Starches or amylaceous substances are contained in 
numerous plant drugs. You are acquainted with corn starch, 
laundry starch, arrow root, and perhaps other kinds of starch. 
Similar starches are found in drugs. 

Starch consists of little granules so small that they can be 
well seen only w T ith the aid of a good microscope. The size, 
form and markings of the starch granules differ according to 
the plant in which the starch is contained. Hence many drugs 
may be identified by their peculiar starch granules. 

Starch in its normal condition is insoluble in water, alcohol, 
ether and other simple solvents. But when starch is heated it 
is altered in properties and becomes soluble. With hot water 



ABOUT DRUGS. 335 

it forms a translucent mucilaginous solution or paste, according 
to the proportions of the two ingredients. When boiled with 
water to w r hich a little sulphuric acid has been added, the starch 
is converted into glucose (hot"). 

When dry starch is subjected to high heat it is converted 
into a gummy, water-soluble substance called dextrin. 

1093. Gums. — Two gums are contained in the Pharmaco- 
poeia. They are acacia and tragacanth. But there are several 
so-called inucilaginous drugs in the official materia medica. 
"Mucilaginous drugs" are drugs containing considerable quan- 
tities of gum and from which mucilages or mucilaginous infu- 
sions can be made. Thus the Pharmacopoeia contains mucilages 
made of quince seed, sassafras pith and slippery elm bark, as 
well as mucilages of acacia and tragacanth. There are also 
other drugs containing large quantities of gum or vegetable 
mucilage, as, for instance, althaea, flaxseed, senna, buchu, etc. 

1094. Gum, or vegetable mucilage, is a substance which 
either dissolves or swells in water, forming, if the quantity of 
gum is sufficient, a thickish, viscous, sticky solution, or a jelly- 
like paste, called a mucilage. The various kinds of gums, dif- 
fering according to their source, are grouped into two classes: 
1, those which, like acacia, are entirely soluble in water, form- 
ing perfect or homogeneous solutions; 2, those which, like trag- 
acanth, simply absorb a large quantity of water, swelling in it 
so as to form translucent gelatinous masses or pastes, but do 
not form perfect or homogeneous solutions. 

1095. Nearly all plants and plant drugs contain more or 
less gum or vegetable mucilage, which is formed by the meta- 
morphosis of plant tissues, as, for instance, of seed coats, on the 
inner surface of inner barks, etc.; or, in large accumulations, 
by the breaking down of plant tissue. 

1096. Gum is hard when dry; does not soften, but, on the 
contrary, hardens when heated, and if the temperature is raised 
higher the gum becomes decomposed charred or carbonized, 
but does not ignite and burn with a flame. 

Gums in solution readily ferment or become sour. 



336 ABOUT DRUGS. 

Gum is insoluble in alcohol, ether, chloroform, volatile oils 
and fixed oils. 

1097. The term " gum " is very generally misapplied. Thus 
we hear camphor, aloes, opium, guaiac, copal, kino, catechu, 
asafcetida, and many other substances called gums. But noth- 
ing that is soluble in alcohol or diluted alcohol can be a gum. 

1098. Gums and mucilaginous drugs are used for preparing 
demulcent drinks and injections, to hold insoluble substances 
in suspension in mixtures, as binding excipients in pill masses 
and troches, etc. 

1099. Pectinous substances are contained in very many 
fruits, and often also in other plant parts. The most striking 
property of pectin is that it forms jelly. Jellies can be made of 
fruits because they contain so much pectin. Pectin is, like gum, 
water-soluble, but not soluble in alcohol, and it readily under- 
goes fermentation. 

1100. Sugars of various kinds exist in plants, and also in 
animal substances, as in milk and honey. They are more or 
less sweet to the taste, cane sugar being the sweetest, and milk 
sugar the least sweet. 

Sugars are always water-soluble, but milk sugar is not freely 
soluble in water, while other sugars dissolve in such large pro- 
portion as to form very thick syrups. 

Sugar is also alcohol soluble to a limited extent. A satu- 
rated water solution of sugar can be mixed with alcohol without 
separation of the sugar from its solution. 

1101. Ordinary white sugar is "cane sugar," saccharose, or 
sucrose. Beet-root sugar, sorghum sugar and maple sugar are 
precisely the same kind of sugar as that obtained from the 
sugar cane; but maple sugar is mixed with other substances 
derived from the maple sap which give it its peculiar agreeable 
flavor; when purified it can not be distinguished from cane 
sugar, nor can pure sorghum sugar and pure beet root sugar be 
recognized as in any manner differing from the refined sugar of 
the sugar cane. 



ABOUT DRUGS. 337 

Rock candy is crystallized cane sugar or saccharose. Milk 
sugar is also crystallizable. 

Grape sugar is the non-crystallizable sugar contained in 
grapes and many other fruits. It is also frequently called 
glucose. But the term " glucose " is now generally applied to 
the sugar manufactured from starch (1092). 

The saccharine substances used in pharmacy include: cane 
sugar, milk sugar, honey and manna. 

1102. Sugars belonging to the class known as "glucoses" 
have the composition C 6 H 12 6 , and readily undergo fermenta- 
tion. Sugars belonging to the class called "saccharoses" have 
the composition C^H^On, and do not ferment unless first 
changed into glucose sugar. 

The products of the fermentation of sugar are alcohol and 
carbon dioxide. 

But fermentable sugar does not undergo fermentation when 
in the form of very dense syrup, while even cane sugar rapidly 
passes through the glucose stage and ferments if in the form of 
a weak water-solution. In fact a syrup of sugar, or simple 
syrup made of pure white sugar, will keep in warm weather 
only if so strong as to contain nearly two-thirds sugar. The 
official " syrup " is a solution of 65 pounds of sugar in 35 pounds 
of water, and is not too concentrated, for it would ferment in the 
summer season if weaker. 

Contact with air is a necessary condition to the fermentation 
of sugars. A weak solution of sugar ferments because it dis- 
solves air; but a dense syrup can not contain air and, therefore, 
does not ferment. 

1103. Sugar is used in pharmacy and medicine for three pur- 
poses: 1, as a diluent; 2, to sweeten medicinal preparations; 3^ 
to preserve organic medicinal substances from fermentation and 
other chemical changes. Both ordinary sugar (cane sugar and 
beet sugar) and milk sugar are used as diluents of powders. 

Sugar is much used to sweeten medicinal preparations, as 
in lozenges, confections, syrups, mixtures, etc. 



3$& ABOUT DRUGS. 

It preserves moist drugs and preparations by taking up the 
moisture forming a thick syrup or a coating of sugar by which 
the moist organic matter is enveloped and air excluded. 

1104. Albuminous matters are nitrogenous substances 
soluble in water when in their normal condition but coagulating 
when heated. A typical example of albumin is furnished by 
the white of egg; as taken from a fresh egg it is transparent, 
liquid, and water-soluble; but when boiled it becomes white, 
opaque, solid, insoluble, and this change is called coagulation. 
There are similar substances contained in plant drugs and 
called vegetable albumi?z, or albuminoids. The white fleshy portion 
of the almond is a vegetable albumin which has received the 
name emulsin, and sometimes the name synaptase. 

Albuminous substances do not ferment, but they undergo 
putrefaction. Their presence in certain pharmaceutical prepara- 
tions is, therefore, to be avoided, and they may be coagulated 
and removed by heat, or by the use of alcohol in which albumin 
is insoluble. 

1 105. Fixed oils or fats. — There are many different kinds 
of fixed oils or fats employed in pharmacy and medicine, espe- 
cially in the preparation of ointments, cerates, liniments, sup- 
positories, etc. Fats are also used in the manufacture of soaps. 

Among the most familiar examples of fixed oils or fats are: 
lard, butter, suet, tallow, wax, spermaceti, lanoleum, cacao but- 
ter, lard oil, cotton seed oil, mustard seed oil, olive oil, castor 
oil, cod liver oil, flaxseed oil, etc. 

1106. Fixed oils are all absolutely insoluble in water; with 
rare exceptions (castor oil and croton oil) they are but slightly 
soluble in alcohol, readily soluble in ether, disulphide of carbon, 
benzol and benzin; and they form true soaps with the alkalies. 

Nearly all the common fixed oils or fats consist chiefly of 
the oleate, stearate and palmitate of glyceryl. Glyceryl is a tri- 
valent hydrocarbon radical C 3 H 5 . Its hydrate is familiar to us 
under the name oi glycerin, C 3 H 5 (OH) 3 . The oleate of glyceryl 
is often called olein, and olive oil is nearly all oleate of glyceryl, 
or olein. Chemically considered the oleate of glyceryl is a 






ABOUT DRUGS. 339 

salt. It is a very fluid fat, and all liquid fats or fixed oils con- 
tain it, their fluidity being proportional to the percentage of 
olein, while the solid fats contain greater proportions of the 
stearateof glyceryl (stearin) and palmitate of glyceryl (palmitin). 

Oleic acid, stearic acid and palmitic acid, are always made 
from fats; their glyceryl salts are the true fats; their salts with 
potassium and sodium are soft or hard soaps; and their salts with 
the heavy metals are the true plasters. 

When perfectly pure the fats are usually colorless or white, 
odorless, tasteless, perfectly bland, without any medicinal effect. 
They always have a greasy or unctuous feel, are lighter than 
water so that they always float upon it, and they are non-volatile 
or fixed so that they can not be distilled, and when dropped 
upon clean white paper, leave a permanent stain. 

1 107. The liquid fixed oils or fats are classified into drying 
oils, and non-drying oils. The drying oils harden or dry upon 
exposure to the air in thin layers, as is the case with flaxseed oil; 
the non-drying oils like oil of almond never dry or harden. 

1108. Castor oil is a remarkable fixed oil because unlike all 
other fixed oils it is entirely soluble in or miscible with strong 
alcohol in all proportions forming perfectly clear mixtures. 
Croton oil, when old, is also soluble in alcohol to a considerable 
extent but forms turbid solutions or mixtures with it. 

1109. Under the combined influence of moisture, air, and 
warmth most of the oils become rancid, especially the animal fats. 
When oleic acid, lard, and other fatty substances become rancid 
they contain oxyoleic acid, have an offensive odor, and are irrita?it 
instead of bland. They are then unfit for any medicinal uses. 

1110. Fixed oil is always contained in seeds. Hence drugs 
consisting of seeds sometimes require special treatment in mak- 
ing solid extracts and other pharmaceutical preparations of them, 
for if their active constituents are such as require a strongly 
alcoholic menstruum for their extraction a considerable quantity 
of fixed oil or grease will also be simultaneously dissolved by 
the menstruum, and the product rendered greasy. Weak alco- 
hol does not extract the fixed oil. But the fat may often be 



34° ABOUT DRUGS. 

removed from the seed with ether, before extracting the medi- 
cinal constituents; or if the fixed oil is extracted by the alcohol 
together with the active constituents, it can be separated from 
the product afterwards. 

1111. Organic acids are contained in all plants. In some 
fruits there are large quantities of fruit acid, as tartaric, citric, 
malic, succinic and oxalic acids. But these acids do not possess 
any decided medicinal action, except that their salts are laxative 
or cathartic, or are used as cooling drinks or fever-mixtures, or 
as mild diuretics. 

Other organic acids occurring in comparatively small quan- 
tities are numerous in the plant world, but there is no import- 
ant plant drug possessing decided physiological effect that has 
been shown to owe its medicinal action to any organic acid. 

1112. Volatile Oils are a numerous and mixed class of sub- 
stances widely distributed among the plants. They seem to 
occur in nearly all plants, although generally in extremely small 
amounts, and although they are more common and abundant 
in certain fruits and flowers, they occur also in leaves and all 
other plant parts. 

The volatile oils contained in the Pharmacopoeia are many 
and include such typical representatives of the whole class as 
the oils of: turpentine, lemon, orange, anise, peppermint, cinna- 
mon, sassafras, cloves, wintergreen and camphor. 

There are also many drugs containing volatile oils as their 
most important constituents, as, for instance: cloves, carda r 
mom, buchu, eucalyptus, etc. 

1113. Volatile oils are generally liquid at ordinary tempera- 
tures, have an aromatic odor, are very slightly soluble in water 
but generally readily soluble in alcohol and ether, they have a 
pungent taste, and are volatile so that they can be easily dis- 
tilled and do not leave a permanent stain when dropped on 
paper. 

Volatile oils are also called "essential oils," and "ethereal 
oils," and the terms u otto" and " attar " have recently been 
proposed to distinguish volatile oils from fixed oils. There 



ABOUT DRUGS. 341 

is no similarity between fixed oils and volatile oils except that 
both have an "oily appearance " and are immiscible with water. 
Volatile oils are not salts; they contain neither glyceryl nor fat 
acids. But a large number of the volatile oils are saturated 
hydrocarbons of the series called terpenes, having the formula 
(C 10 H 16 ) n ; other volatile oils are oxidized hydrocarbons, and 
some volatile oils contain sulphur, cyanogen, and other radicals. 
Most of the volatile oils are lighter than water; but some of 
them, as the oils of cloves and wintergreen, are heavier. 

1114. Many of the volatile oils consist of a liquid portion 
called the elceopten, and another portion called the stearopten, 
which is solid when separated from the elseopten. The stear- 
optens of volatile oils are often called camphors, and ordinary 
camphor is a stearopten. 

As a rule a volatile oil is not a single definite substance, but 
a mixture of several different kinds of substances. 

1115. Most of the volatile oils of the terpene series, if not 
all of them, deteriorate rapidly unless kept in small, filled, 
tightly stoppered bottles in a dark, cool place. If exposed to air, 
light and warmth they resinify — that is, they take up oxygen, 
and as they are oxidized resinous products are formed by which 
the volatile oils are changed in composition, color, density and 
odor. 

1116. Volatile oils are obtained from the plants and plant 
parts either by distillation (with the aid of water), or by expres- 
sion, or by extraction with alcohol or with fixed oils. 

1 1 17. Nearly all flowers, fruits, herbs, leaves, and other 
plant parts possessing an aromatic odor contain one or more 
volatile oils, to which their odor is due. All volatile oils, and 
plant drugs containing them, are aromatic stimulants, and some 
of them are anthelmintics, while nearly all act upon the kidneys. 

1118. Resins are solids or semi-solids, they soften and 
then liquefy when heated; they are non-volatile, readily combus- 
tible, being easily ignited, burning with a sooty, smoky flame; 
insoluble in water, alwavs alcohol-soluble, and often also soluble 



342 ABOUT DRUGS. 

in ether, benzin, volatile oils, fixed oils, and chloroform. They 
are generally weak acids, and formed by the oxidation of volatile 
oils. They do not contain nitrogen. 

Resins may be classified into dry, hard resins, which are gen- 
erally amorphous and of a glassy fracture, though sometimes 
crystalline, and as a rule not acrid or irritating when applied to 
the skin; and soft resins, which are usually acrid, non-drying. 

Some of the acrid resins are hard, however. There are sev- 
eral resins so acrid as to vesicate the skin. Other resins are 
cathartics. 

1119. Resins are used in the preparation of some plasters,, 
cerates and even ointments. Solutions of resins in oil of tur- 
pentine, benzin, or alcohol are varnishes. 

Resins, being weak acids, form soap-like compounds called 
resin-soaps with the alkalies. 

1120. Among the common resins are ordinary "rosin," 
copal, dammar, mastic, sandarac, guaiac resin, scammony, amber, 
benzoin, shellac, so-called " spruce-gum," burgundy pitch, etc. 

1121. As the resins are formed by the oxidation of volatile 
oils, and as the volatile oils are mixtures, the resins thus pro- 
duced are also mixtures. Moreover, resins and volatile oils are 
commonly associated together. Oleoresitis are mixtures of vola- 
tile oil and resin; thick turpentine, Canada turpentine, copaiba, 
etc., are oleoresins. Balsamic resins are such resins as contain 
either benzoic or cinnamic acid, or both, as benzoin and tolu; 
and balsams are fluid balsamic resins, as " balsam of Peru and 
storax." 

1122. Spices are drugs containing agreeable pungent oleo- 
resins, or pungent resins, or pungent volatile oils. They are 
mostly oleoresinous drugs. But there are also several oleo- 
resinous drugs which are used solely for medicinal purposes and 
are not spices or condiments. 

Capsicum, pepper, cubeb, asarum, aspidium, cypripedium, 
iris versicolor, ginger, lupulin, are oleoresinous drugs. 

1123. Gum-resins are mixtures of gum and resin, and they 
usually also contain small quantities of volatile oil, which is fre- 



ABOUT DRUGS. 343 

quently the only constituent of any medicinal value. The gum. 
resins of the Pharmacopoeia are ammoniac, asafcetida, gal- 
banum, gamboge and myrrh. 

1 124. Coloring matters are very generally of a resinous nature. 
Thus the green coloring matter of leaves, called chlorophyll, is 
resinous, alcohol soluble, insoluble in water. Other coloring 
matters — red, yellow, and brown — are more frequently alcohol 
soluble than water soluble. Hence alcoholic tinctures and 
extracts are as a rule more highly colored than aqueous prepa- 
rations. 

1125. Neutral principles, not belonging to any of the dif- 
ferent classes of proximate principles enumerated in this chap- 
ter, are of a very miscellaneous chemical character. They are 
often of the class known as glucosides (977), sometimes weak 
acids, sometimes other compounds. 

As to their physical properties many neutral principles are 
crystallizable while others are amorphous ; many are water- 
soluble and a still greater number soluble in diluted alcohol or 
in undiluted alcohol, but others may be insoluble in one of these 
liquids. 

A large number of the neutral principles are purely bitter 
stomachic tonics ; others are acrid, or even narcotic ; and others, 
again, seem to be wholly inert, as, for instance, asparagin. 

The Glucosides possess medicinal activity more frequently 
and more decidedly than other neutral principles contained in 
plant drugs. 

Among the most common neutral principles of plant drugs 
are salicin, populin, phlorizin, amygdalin, saponin, coumarin, 
aloin, cathartin, and elaterin; and among the important drugs 
whose active principles belong, to this class are rhubarb, senna, 
senega, squill, digitalis, brayera, aloes, and colocyrith. 

1126. Many of the acrid drugs, such as squill, digitalis, 
senega, etc., are drugs containing glucosides. But there are 
also acrid drugs which owe their acridity to acrid soft resin or 
some acrid volatile oil, or to some acrid alkaloid. 



344 ABOUT DRUGS. 

1127. Astringent Drugs contain tannin. Tannin, or tannic 
acid, is a peculiar neutral principle or a weak acid, having a 
powerfully astringent effect. Tannin darkens iron salts, and 
forms insoluble compounds with all metallic salts. Ink is made 
by mixing decoction or infusion of nutgall or madder (contain- 
ing tannin) with solutions of sulphates of iron. Tannin also has 
the property of tanning hides, forming a tough substance called 
leather when it acts upon the tissues of the fresh rawhide. 
Insoluble compounds are formed by tannin also with a number 
of other organic substances, as gelatin, alkaloids, etc. 

Among the most important of our astringent drugs are 
tannin itself, nutgall, oak bark, logwood, catechu, kino, krameria, 
geranium, rubus, rhus glabra, and uva ursi. 

1128. Alkaloids are the most powerful of all the active 
principles of plant drugs. 

Alkaloids are organic bases having an alkaline reaction on 
test paper and capable of combining with and neutralizing the 
acids to form salts. They are called alkaloids because they 
resemble the alkalies in the before-mentioned properties. 

1129. Many alkaloids are formed and contained in growing 
plants; others are not found in the living plants but formed by 
certain reactions in the contents of plant juices after death, as 
when morphine and the other opium alkaloids are formed during 
the process of drying the juice of the poppy capsule. 

Among the most important of our alkaloids are quinine, mor- 
phine, strychnine, atropine, cocaine, physostigmine, and aconi- 
tine. Among the most important drugs whose medicinal value 
depends upon alkaloids we have aconite, belladonna, coffee, 
cinchona, colchicum, conium, erythroxylon, gelsemium, hydrastis, 
hyoscyamus, ipecacuanha, lobelia, nux vomica, opium, physo- 
stigma, pilocarpus, sanguinaria, stramonium, tobacco, and vera- 
trum viride. 

Over two-thirds of all known plant drugs containing alka- 
loids are poisonous. 

1130. Alkaloids in the free state are generally alcohol- 
soluble, rarely water-soluble; but their salts with the stronger 



ABOUT DRUGS. 345 

acids are generally water-soluble, not generally alcohol- 
soluble. 

Alkaloids and their salts are bitter or acrid to the taste. 

They may be classified according to their chemical composi- 
tion into two groups ; 1, the amines', and 2, the amides. 

The amines consist of carbon, hydrogen and nitrogen, and 
are called ternary alkaloids for that reason. They are liquid, vola- 
tile, odorous. Nicotine (the alkaloid of tobacco), coniine (the 
alkaloid of conium), and lobeline (the alkaloid of lobelia), are 
amines. 

The amides contain oxygen as well as carbon, hydrogen, and 
nitrogen. They are accordingly called oxygenated or quaternary 
alkaloids. They are solids, not volatile, odorless. By far the 
greater number of alkaloids belong to this class. 



CHAPTER LXIV. 

ROOTS, RHIZOMES, CORMS AND BULBS. 

1131. Aconitum. Aconite. 

From Aconitum Napellus {Ranunculacecz). 

Mountain districts of Europe and America. 

Tuberous, tapering, about 2 in. long, x / z to ^ in. thick at the top; very 
•dark grayish-brown exteriorly, whitish interiorly; odorless; taste first insipid, 
afterwards acrid; produces tingling and numbness in the throat. 

Active principle — The alkaloid aconitine. 

A cardiac sedative. 

Dose of the drug 1 to 2 grs.; Abstract, ^to 1 gr. ; Extract, }£ to l / z gr. ; 
Fluid Extract, ^ to 2 min.; Tincture, 1 to 5 min. 

Poisonous effects. — The action of an overdose is rapid. Weakness, 
stupor, and paralysis are the successive symptoms. 

Death results from paralysis of the muscles of respiration and of the heart. 

Antidotes. — The patient should lie down, the stomach be emptied, and 
alcohol, ether, or spirit of ammonia administered. 

1132. Allium. Garlic. 

The fresh bulb of Alliwn sativum (Liliacece). 



346 ABOUT DRUGS. 

The garlic consists of about 8 wedge-shaped bulblets. 
Strong, offensive odor and a disagreeable, acrid taste. 
Contains acrid volatile oil. . 

1133. Althaea. Marshmallow. 
From Althaa officinalis (Malvacece). 
Continental Europe. 

Cylindrical, or nearly so, 3 to 6 in. long, ]/ z in. in diameter, deep- 
wrinkled; decorticated, white, fibrous, starchy; odor faint; taste sweetish, 
mucilaginous. 

Demulcent. 

1 134. Aspidium. Male Fern. 

The rhizome of Aspidium Filix-mas and A. marginale (Filices). 

All temperate countries. 

Pieces about 3 to 6 in. long, about % to 3^ in. thick; either peeled or 
covered with the remnants of the stipes; should be pale green, all brown 
portions to be removed ; odor disagreeable though faint ; taste slightly 
astringent, bitterish, acrid, disagreeable. 

Contains volatile oil, resin, fixed oil and filicic acid. 

It is a tcenicide. 

The Oleo-resin is the only official preparation; dose, 10 to 30 min. 

1135. Belladonnas Radix. Belladonna Root. 
F r o m A tropa Bella donna ( Sola nacece) . 

Central and Southern Europe. 

Long, generally tapering pieces, y 2 in. or more thick, wrinkled length- 
wise; grayish exteriorly, whitish interiorly; odor faintly narcotic; taste bit- 
terish, finally acrid; should break with a nearly smooth fracture; tough, 
woody, splintery roots are to be rejected. 

Active principles. — The alkaloids atropine, belladonnine and hyscyamine.. 

Mydriatic, anodyne, antispasmodic, cardiac and vaso-motor stimulant. 

Dose. — Fluid extract, 1 to 3 min. 

Poisonous effects. — Headache, vertigo, greatly disturbed vision, delir- 
ium, motor paralysis, stupor, convulsions 

Antidotes. — Evacuation of the stomach, followed by the administration 
of opium, morphine or physostigma. 

1 136. Calamus. Sweet Flag. 

The unpeeled rhizome of Acorus Calamus (Aracece). 

The United States. Europe. 

Long pieces, about % in. thick, wrinkled lengthwise; exteriorly brown- 
ish, interiorly whitish- spongy, fracture short; odor aromatic; taste sweetish,, 
bitterish, pungent. 



ABOUT DRUGS. 347 

Contains volatile oil, resin and the bitter principle acorin. 

Aromatic stimulant and tonic. 

Dose of the Fluid Extract, 15 to 60 minims. 

1 137. Calumba. Columbo. 

The root of Jateorrhiza Calumba (Menispermacece). 

Eastern Africa. 

Circular slices, 1 to 2 in. diameter, about \ \.o\ in. thick; cut surfaces con- 
cave; outer edge brownish-gray, broad surface yellowish-gray and often bright 
yellow near the epidermis; fracture short; odor faint; taste bitter, mucilaginous. 

Constituents. — The bitter principles calumbin, calumbic acid and berberine,. 
Also starch and mucilage. 

A bitter stomachic tonic. 

Doses. — Fl. Extr. 15 to 75 min.; Tinct. , 1 to i\ fi. dr. 

1138. Cimicifuga. Black Snakeroot. 

Rhizome and rootlets of Cimicifuga racemosa (Ranunculacece) . 
The United States. 

Rhizome short, thick, branched, covered with many long rootlets, 
brownish-black, nearly odorless, bitter, acrid. 

Contains a very acrid neutral principle and resin. 

Dose. Fl. Extr., 10 to 30 minims; Tinct., 30 to 75 minims. 

1139. Colchici Radix. Colchicum Root. 
The corm of Colchicum autumiiale (Melanthacece). 
Middle and Southern Europe. 

Ovoid, flattish, with a groove on one side. Generally sliced. Exteriorly 
brownish, somewhat wrinkled; interiorly white, starchy, odorless, sweetish, 
bitter, acrid. 

Active principle. — The acrid alkaloid colchicine. 

Alterative and diuretic. 

Dose. — Extract, % to i\ grains; Fluid Extract, 2 to 5 minims; Wine, 10 to 
30 minims. 

Poisonous effects. — Pain in the stomach and bowels; watery stools; 
collapse. 

Antidotes. — Emetics, purgatives, and afterwards opium and alcoholic 
stimulants. 

1 140. Gelsemium. Yellow Jasmine. 

Rhizome and rootlets of Gelse??iiu??i scmpervirens {Loganiacea), 

Southern United States. 

Branched rhizomes about \ to 1 inch or more thick; rootlets longer and 
much thinner; brownish-yellow; tough, woody fracture; heavy odor, bitter 
taste. 



348 ABOUT DRUGS. 

Active principle. — The poisonous alkaloid Gelsemine. 

A motor and sensor depressant and cardiac sedative. 

Poisonous effects. — Depres-sion, respiration and heart action becoming 
labored; cerebral disturbance; general paralysis. 

Antidotes.— After evacuation of the stomach, alcoholic stimulants, spirit 
of ammonia; artificial warmth and respiration; digitalis and belladonna. 

1141. Gentiana. Gentian. 
From Gentiana lutea (Gentianacece) . 
Central and Southern Europe. 

Pieces about 2 to 3 inches long, % inch thick; thicker pieces usually split; 
•deeply wrinkled lengthwise, more or less distinctly marked by transverse 
rings; exteriorly dark yellowish-brown, interiorly lighter. Brittle when dry, 
flexible when damp; odor characteristic, somewhat aromatic; intensified by 
moisture; taste bitter. 

Contains the bitter principle gentio-picrin. 

Also genti sic acid which darkens iron salts. 

Gentian is a bitter stomachic tonic. 

1 142. Glycyrrhiza. Licorice Root. 
From Glycyrrhiza glabra (Leguminosce). 
Southern Europe. 

Long, cylindrical pieces, from 34 to 1 inch in diameter, wrinkled length- 
wise, exteriorly (the bark) grayish-brown, interiorly yellow; fracture woody, 
coarsely fibrous; inodorous; taste sweet, leaving a somewhat acrid after- 
taste. 

Contains the sweet substance called glycyrrhizin; also starch, gum, and 
some acrid resin. 

Preparations. — Extract, Fluid Extract, Ammoniated Glycyrrhizin. Com- 
pound Powder. 

1143. Hydrastis. Golden Seal. 

The rhizome and rootlets of Hydrastis canadensis {Ranuncu- 
lacece) . 

The United States. 

About 1% inches long, rhizomes, 34 inch thick, wrinkled, yellowish-gray; 
fracture short, orange-yellow; rootlets thin, brittle; odor faint; taste bitter. 

Active Principles. — A white alkaloid, hydrastine, and the yellow, alka- 
loid berberine, both bitter. 

Tonic, diuretic, etc. 

Preparations. — Fluid Extract and Tincture. 



ABOUT DRUGS. 349 

1144. Ipecacuanha. Ipecac. 
From Cephae'lis Ipecacuanha {Rubiacea:). 
Brazil. 

Crooked pieces, about 3 to 5 inches long, yk inch thick; dull grayish-brown, 
finely wrinkled, marked by numerous rings, close together, bark thick, often 
broken transversely; easily separated from the thin, tough, ligneous cord; odor 
not strong, but quite characteristic, nauseous; taste bitterish, acrid, sickening. 

Active principle. — The alkaloid emetine. 

The drug is emetic; in small doses expectorant and diaphoretic. 

Doses — Emetic: Powder, 15 to 30 grs.; Fluid Extract, 15 to 30 minims; 
Syrup, 4 to 6 fluidrachms; Wine, 3 to 5 fluidrachms. Expectorant: Fluid 
extract, 1 to 4 minims; Syrup, 1 to 2 fluidrachms; Wine, 10 to 30 minims. 

1145. Iris Versicolor. Blue Flag. 
The rhizome of Iris versicolor (Iridacecs). 
Middle and Southern United States. 

Long, jointed pieces, cylindrical or flattish. marked by scars, wrinkled, 
annulated, grayish-brown; taste acrid, nauseous. 
Contains volatile oil and acrid resin. 
Purgative and diuretic. 
Dose. — Extract, % to 1 gr. ; Fluid Extract, 30 to 60 minims. 

1 146. Jalapa. Jalap. 

The tuber of Exogonium purga (Convolvulacea). 

Mexico. 

Turnip-shaped, or oblong, varying in size, larger roots split, wrinkled, 
with short transverse ridges, dark brown, hard, heavy, interiorly pale grayish- 
brown; fracture smooth, resinous; odor slight sweetish, but quite peculiar, 
smoky; taste sweetish, acrid. 

Each 100 grains of Jalap must yield at least 12 grains of resin; and not 
more than 1.2 grains of that resin should be soluble in ether. 

Contains the cathartic resin called Convolvulin. 

Purgative 

Dose. — Powder 10 to 20 grs.; Abstract. 5 to 10 grs.; Alcoholic Extract 2 to 
8 grs.: Fluid Extract, 10 to 20 minims; Compound Powder, 10 to 30 grs.; 
Resin, 2 to 6 grs. 

1 147. Krameria. Rhatany. 

From Krameria triandra and K. tomentosa (Polygalacece). 
Northern parts of South America. 

Knotty, irregularly shaped, branched roots, sometimes about one inch or 
mere thick: rust-brown; but the better Krameria consists of long, cylin- 



^ZO ABOUT DRUGS. 

drical roots not over }$ to j£ inch thick, dark purplish-brown : bark thick, and 
should constitute about one-third of the drug; wood tough, light brownish. 

Contains k> anuria-tannic acid (about 20 per cent.). 

Astringent. 

Dose. — Extract, ^to 15 grs.: Fluid Extract, 30 to 60 minims; Syrup, % to 
4 fluidrachms; Tincture % to 3 fluid drachms. 

1148. Leptandra. Culver's Root. 
From Leptandra virgitdca \Scrophulariacca?). 

The United States. 

Rhizome from 4 to 6 inches long, and about % inch thick, somewhat 
irregular in shape, blackish-brown, with cup-shaped scars above ; hard, with 
a woody fracture, wood yellow; rootlets thin, wrinkled, brittle; inodorous, 

bitter, acrid. 

Contains the acrid principle called :z ?;>::>: t:c;e:her with acrid rer.r 
Dose. — Extract 1 to 2 grs.; Fluid Extract 30 to 60 minims. 

1 149. Pareira. Pareira Brava. 

From Chondodendron tomentosum (3femsper?nacece). 

Brazil and Peru. 

Round, crooked pieces, about 4 to 10 inches long, from % to 3 inches 
thick ; exteriorly brownish-gray ; furrowed lengthwise, with transverse ridges 
and fissures ; interiorly paler brown, marked by two or more irregular, con- 
centric circles of distinct rays. 

Contains the bitter alkaloid buxinc, also called " cissampeline. " or 
""pelosine ." 

Tonic and diuretic. 

Dose of Fluid Extract, 30 to 60 minims. 

1150. Phytolacca^ Radix. Poke Root. 
From Phytolacca decandfj (Phytclaccacccc). 
The United States. 

Large, usually sliced, fleshy, wrinkled, light grayish ; hard : fracture 
fibrous, the wood bundles in concentric circles; taste sweetish, acrid. 

Active principle possibly an alkaloid, (domains acrid resin. It is nar- 
cotic. 

Dose c: Fluid Extract. 1: to y: minims. 

1151. Podophyllum. Mandrake. 

Rhizome and rootlets oi P c dophyllum peltatum (Berberidacca). 
The United States. 

Long jointed cieces. each joint about i 1 , to 2 inches long, about % inch 
or mere thick : a circular stir : ~. the upper side at each joint, rootlets on the 



ABOUT DRUGS. 351 

■under surface, or small white scars left after them ; smooth or slightly wrinkled; 
exteriorly light orange brown, interiorly nearly whitish; odor slight, but 
peculiar; taste sweetish, bitter, acrid. 

Contains from 4 to 5 per cent, of resin, called " resin of podophyllum," 
or " podophyllin," and consisting of various substances. 

It is purgative. 

Dose. — Powder, 8 to 30 grains; Abstract, 3 to 10 grains; Extract, I to 4 
grains; Fluid Extract, 8 to 20 minims; Resin, 1-6 to ]/ 2 grain. 

1152. Rheum. Rhubarb. 
From Rheum officinale (Polygonacetz) . 
Thibet and China. 

Large, thick pieces of various shapes and sizes, deprived of the 
outer layer, exteriorly smooth, reddish-brown, covered with a light yellowish- 
brown powder; interiorly of an irregularly marbled appearance, orange- 
yellow and white veins, striae, or rays alternating; odor peculiar, taste 
bitterish, somewhat astringent; when chewed, rhubarb is g.'itty from crystals 
of calcium oxalate. 

Active principles. — Several resinous cathartic principles are contained in 
rhubarb. Among these are: Chrysophan, chrysophanic acid, cathartin, tmodin. 

Has a cathartic effect, followed by an astringent action due to rheo-tannic 
acid. 

Preparations and dosee. — Powder, 10 to 30 grs.; Extract, 5 to 15 grs.; 
Fluid Extract, % to 1% fluidrachms; Compound Powder, 15 to 60 grs.; 
Syrup, 1 to 4 fluidrachms; Aromatic Syrup, 1 to 2 fluidrachms; Tincture, 
Aromatic Tincture and Sweet Tincture, each 1 to 6 fluidrachms; Wine, 1 to 
4 fluidrachms. 

1153. Sanguinaria. Bloodroot. 

The rhizome of Sanguinaria canadensis (Papaveracece). 

The United States. 

About two inches long, cylindrical, tapering somewhat at the ends, about 
Y^ inch or more thick, somewhat wrinkled; brown-red; fracture short; taste 
bitter, extremely acrid. 

Contains the acrid, narcotic alkaloid sanguinarine. 

Used as an expectorant. 

Dose. — Vinegar, 10 to 30 minims; Fluid Extract, 5 to 15 minims; Tinct- 
ure, 10 to 60 minims. 

1154. Sarsaparilla. Sarsaparilla. 

From Smilax officinalis, S. medica, and other species of Smilax 
(Smilacece). 

Mexico, and Central and South America. 



35 2 ABOUT DRUGS. 

About y z inch thick, very long, cylindrical, deeply wrinkled lengthwise, 
grayish-brown or orange-brown ; interiorly starchy, somewhat horny ; odor 
very faint ; taste mucilaginous, bitterish, acrid. 

The knotty rhizome or "chump," if present, should be removed. 

Contains the acrid principle saponin, also called "parillin," or " sarsa- 
parillin." 

Alterative. 

Preparations. — Fluid Extract, Compound Fluid Extract, Compound Syrup 
and Compound Decoction. 

1155. Scilla. Squill. 

The bulb of Urginea Scilla (Li Hoc e a). 

Mediterranean coasts. 

Slices about 2 inches long, % inch thick, yellowish-white, or reddish- 
white, slightly translucent, brittle when dry, tough and flexible when damp; 
inodorous ; taste mucilaginous, bitter, acrid. 

Contains several acrid substances of which the most important are 
scillitoxin, scillipicrin, and scillin. Squill also contains much mucilage. 

Diuretic and expectorant. 

Dose. — Vinegar, 10 to 30 minim ; Fluid Extract, 3 to 15 minutes ; Syrup 
and Compound Syrup, 30 to 60 minims ; Tincture, 8 to 30 minims. 

1 156. Senega. Seneka Snakeroot. 
From Poly gala Senega (Polygalacece). 
Middle and Southern United States. 

About 4 inches long, with a knotty crown, branched, spindle-shaped, 
somewhat tortuous, with a keel running spirally from crown to apex;' 
Exteriorly wrinkled lengthwise, slight yellowish-brown or yellowish-gray; 
bark thick; odor slight, but peculiar, disagreeable; taste first insipid, sweetish, 
afterwards acrid. 

Contains the acrid principle saponin, which is also called " senegin," 
"polygalic acid," etc. 

Expectorant and diuretic. 

Dose. — Abstract, 3 to 12 grains ; Fluid Extract, 8 to 20 minims ; Syrup, 
1 to 2 fluid drachms. 

1 157. Serpentaria. Virginia Snakeroot. 
From Aristolochia Serpentaria (Aristolochiacece). 
The Middle and Southern United States. 

Rhizome about one inch long, with remnants of stems on the upper and 
rootlets on the under side; rootlets long, slender, brittle; dull brown, interiorly 
lighter; odor aromatic, camphoraceous, terebinthinate; taste warm, bitterish, 
resinous. 



ABOUT DRUGS. 353 

Contains volatile oil and resin. 

Aromatic stimulant tonic. 

Dose. — Fluid Extract, 30 to 60 minims; Tincture, ^ to 2 fluidrachms. 

1158. Spigelia. Pinkroot. 

From Spigelia marylandica (Loganiacece). 
The United States. 

Rhizome about 2 inches long and ]/% inch thick; scars above, and numerous 
thin, brittle rootlets below; dark brown; slightly aromatic, bitter. 
Contains a bitter principle, volatile oil and resin. 
Anthelmintic. 
Dose of Fluid Extract, 30 to 60 minims. 

1159. Stillingia. Queen's Root. 
From Stillingia sylvatica {Euphorbiacea). 
Southern United States. 

Long pieces, about 2 inches thick, wrinkled, tough, grayish-brown; bark 
thick with numerous resin cells; odor disagreeable; taste bitter, acrid. 
Contains a soft, pungent, acrid resin. 
Alterative. 
Dose of Fluid Extract, 1 to 2 fluidrachms. 

1 160. Taraxacum. Dandelion. 
From Taraxacum De?is-leonis (Cotnpositce). 
Europe and America. 

About 3 to 6 inches long, x / 2 to 1 inch thick, branched head, wrinkled 
lengthwise, exteriorly dark brown when old, lighter when recently dried, 
interiorly yellowish, bark thick and white, with milk-vessels in concentric 
rings; inodorous, bitter. 

Contains the bitter principle iaraxacin and acrid taraxacain. 

Tonic, diuretic. 

Dose. — Extract, 15 to 40 grs.; Fluid Extract, 1 to 3 fluidrachms. 

1161. Valeriana. — Valerian. 

From Valeriana officinalis (Valerianacece). 

Europe. Vermont. 

Rhizome about ^to 1^ inches long, brown, interiorly lighter; rootlets 
numerous, slender, brittle, brown, with thick bark; odor strong, peculiar, 
disagreeable; taste bitter, aromatic, nauseous. 

Contains valeric acid, volatile oil and resin. When fresh it contains much 
volatile oil and little valeric acid: as the drug becomes older the proportion of 
acid increases and the volatile oil diminishes. 

Antispasmodic. 



354 ABOUT DRUGS. 

Dose. — Abstract, 8 to 30 grains; Extract, 10 to 40 grs.; Fluid Extract, % 
to 2% fluidrachms; Tincture, and Ammoniated Tincture, 1 to 4 fluidrachms. 

1162. Veratrum Viride. American Hellebore. 
From Veratrum viride. (Melanthacece). 

Northern United States. 

Rhizome about 2 to 3 inches long, 1 to 2 inches thick, exteriorly blackish- 
gray, interiorly grayish-white; numerous light brown rootlets, from 4 to 6 
inches long and about ^ inch thick; inodorous; powder extremely irritating, 
sternutatory; taste bitter, very acrid. 

Active principles. — The acrid alkaloids jervine, veratroidine ; rubijei-vine, 
and pseudojervine. 

Cardiac sedative. 

Dose. — Fluid Extract, 2 to 5 minims; Tincture, 3 to 10 minims. 

1163. Zingiber. Ginger. 

From Zingiber officinale {Zingiberacece). 

Tropical Asia (Cochin) and the West Indies (Jamaica). 

Rhizomes about x / 2 inch or more broad, flattish, lobed or branched; 
deprived of the epidermis; pale buff -colored; fracture fibrous, starchy, show- 
ing scattered resin cells; odor peculiar, aromatic, pungent; taste hot, spicy. 

Contains volatile oil and resin. 

Carminative. 

Dose. — Fluid Extract, 4 to 30 minims; Oleoresin, 1 to 3 drops; Syrup, 1 
to 2 fluidrachms; Tincture, 30 to 60 minims. 



CHAPTER LXV. 

WOODS, BARKS, ETC. 

1164. Guaiaci Lignum. Guaiac wood. 

The heart wood of Guaiacum officinale (Zygophyllacece) . 

West Indies and South America. 

Heavy, hard, dark greenish-brown, resinous; when heated it emits a 
resinous odor; taste somewhat acrid. 

Contains about 25 per cent, resin. 

Alterative. 

Used in the preparations called Compound Decoction and Compound 
Syrup of Sarsaparilla. 



ABOUT DRUGS. 355 

1 165. Haematoxylon. Logwood. 

The heartwood of Hcematoxylon campechianum^Legumijiosoz). 

Tropical America. 

Heavy, hard, brown-red; odor faint, peculiar; taste sweetish, astringent; 
colors the saliva dark reddish-pink. 

Contains tannin, and a crystallizable, sweet substance called hcemotoxylin. 
The tannin is the valuable constituent. 

Astringent. 

Dose of the Extract, about 10 grains. 

1 166. Quassia. Quassia. 

The wood of Picrcena excelsa (Simarubacece). 

West Indies. 

Yellowish-white chips or raspings; inodorous; intensely bitter. 

Contains the bitter neutral principle quassiin. No tannin is contained 
in it. 

Bitter stomachic tonic. 

Dose. — Extract, 1 to 2 grs.; Fluid Extract, 30 to 60 minims; Tincture, 1 
to 2 fiuidrachms. 

1167. Aspidosperma. Quebracho Bark. 
From Aspidosperma Quebracho (Apocynaceoz). 
Brazil. 

Large pieces, about j{ inch thick, more or less curved, the rough corky 
layer and the inner bark being of about equal thickness; outer bark fissured, 
gray; inner bark fawn-colored; fracture fibrous; inodorous; inner bark (active 
portion) very bitter. 

Active principles: — Several alkaloids, the most important of which are 
mpidospertnine and quebrachine. 

Dose of Fluid Extract, 15 to 45 minims. 

1168. Aurantii Amari Cortex. Bitter Orange Peel. 

The rind of the fruit of Citrus vulgaris ^Aurantiacece). 

Southern Europe. 

Thin, spiral bands or oval, curved pieces, greenish-gray and reddish on 
the outer surface, white on the inner side. Odor agreeable, aromatic; taste 
aromatic, bitter. 

Constituents. — The bitter principle kesperidin and a little volatile oil. 
(This volatile oil is known in commerce as "essence de bigarade.") 

Used as an aromatic, bitter, stomachic tonic. 

Dose. — Fluid extract, 30 to 60 minims; tincture, 1 to 2 fluid drachms. 

H69. Cinchona. Cinchona Bark. 

The bark of any species of Cinchona (Rubiacece), containing 
at least three per cent, of total alkaloids. 



356 ABOUT DRUGS. 

Cinchona Flava. Yellow Cinchona; Calisaya Bark; 
Yellow Peruvian Bark. 

The trunk bark of Cinchona Calisaya. 

Peru an (^Bolivia. Cultivated in India. 

Cinchona Rubra. Red Cinchona; Red Peruvian Bark. 

From Ci?ichona Succirubra. 

Ecuador. Cultivated in Java, Ceylon, etc. 

The Pharmacopoeia recognizes under the general title of 
"Cinchona" any cinchona bark containing at least 3 per cent. 
of the total cinchona alkaloids; it requires the "yellow cin- 
chona " and "red cinchona" to contain at least 2 percent, of 
the alkaloid quinine, without reference to the other cinchona 
alkaloids. 

Yellow Cinchona occurs in flat pieces or quills of various sizes, of a 
light yellowish-brown color; inodorous; taste bitter. 

Dose. — Extract, 10 to 30 grains; Fluid extract, 15 to 50 minims; Infusion, 
6 to 24 fluidrachms; Tincture, y z to 2 fluidrachms. 

Red Cinchona occurs in quills, irregular nieces, or in shavings; dark 
brown red; odor faint; taste bitter, astringent. 

Dose. — Fluid Extract, 15 to 60 minims; Comp. Tincture, ^ to 2 fluid 
drachms. 

Constituents. — Both yellow and red cinchona contain the alkaloids 
quinine, quinidine, cinchonine and cinchonidine; but yellow bark contains a 
greater proportion of quinine than the red bark, while red cinchona contains a 
greater proportion of cinchonidine and cinchonine. Both barks contain a 
peculiar tannin called cinchotannic acid. The red bark contains also a resin- 
ous coloring matter called cinchona red. 

Uses. — Cinchona is a valuable bitter tonic and antiperiodic, it is also 
astringent. 

1170. Cinnamomum. Cinnamon. — Saigon Cinnamon. 

The inner bark of the shoots of some species of Cinnamomum 
(Lauracece). 

Grown in China. 

Saigon cinna?non occurs in regular quills, from \ to nearly 1 inch in 
diameter, exteriorly rough, brownish-gray, light brown on the inner side; 
odor very fragrant, taste sweetish, aromatic, quite pungent, but agreeable. 

Ceylon cinnamon is in long, slender multiple quills, consisting of the thin, 
smooth inner bark; of a light yellowish-brown color. It is of very fine 
flavor. 



ABOUT DRUGS. 357 

Chinese cassia cinnamon is thicker than Ceylon cinnamon, occurs in single 
quills of much thicker bark, darker brown, and of inferior flavor. 
Contains volatile oil. 
Used as an aromatic stimulant and as flavoring ingredient. 

1171. Frangula. Buckthorn Bark. 

From Rhamnus Frangula {Rhamnacece). Must have been col- 
lected at least one year before being used. 
Throughout Europe. 

Quills or troughs about i to f inch in diameter, the bark about 1-24 in. 
thick, brittle. Outer surface smoothish, grayish or brown; inner surface 
smooth, orange or brownish-yellow. Odor faint but peculiar; taste sweetish, 
bitter, disagreeable. Colors the saliva yellow. 

Constituents. — Frangulin, or rhamnoxanthin, which is cathartic; also 
several other laxative and cathartic principles of a resinous character. Old 
bark contains emodin, which is also found in rhubarb. 

Purgative. 

Dose of the Fluid Extract, 1 to 3 fluidrachms. 

1172. Gossypii Radicis Cortex. Cotton Root Bark. 

The bark of the root of the cotton plants, Gossypium herbaceum and other 
species of Gossypium (ATalvacece). 

Southern United States. 

Long, thin, flexible strips, brownish-yellow exteriorly, inner surface 
whitish; tough, fibrous; inodorous; taste somewhat acrid. 

Contains resin, tannin, and red coloring matter. 

Its medicinal properties and uses are similar to those of ergot. 

Dose of the Fluid Extract, 30 to 60 minims. 

1173. Granatum. Pomegranate Root Bark. 

The bark of the root of Punica Granatum (Granatacetz.) 
Cultivated in subtropical countries as on the Mediterranean 
borders. 

Troughs, quills, or fragments of various sizes, mostly in pieces about two 
to four inches long, bark about 1-24 inch thick; outer surface yellowish-gray 
or brownish-gray; inner surface lighter grayish-yellow; inodorous; taste 
astringent, somewhat bitter. Colors the saliva yellow. 

Contains the alkaloid pelletierine, and other alkaloids have also been 
reported as found in this drug. 

It is anthelmintic or taenicide. 

Dose of the Fluid Extract, 30 to 80 minims. 

1174. Mezereum. Mezereum. 

From Daphne Mezereum and other species of Daphne (Thymel- 
acece) . 



358 ABOUT DRUGS. 

Mountain regions of Northern Europe and Asia. 

Long, thin, tough bands, exteriorly brownish-yellow and light greenish, 
on the inner side whitish, shining. Inodorous: extremely acrid. 

Contains soft, acrid resin, and an acrid volatile oil, besides the bitter prin- 
ciple daphnin. 

Preparations. — Extract, Fluid Extract and Ointment: used external 
stimulants and rubefacients. 

1175. Prunus Virginiana. Wild Cherry. 
From Prunus scroti na {Rosacea). 

The United States. 

Wild Cherry Bark is collected in the autumn from medium large branches 
of sound, not too old, trees. The bark from small branches as well as cork- 
covered old bark, must not be used. 

Curved or fiat, irregularly-shaped pieces at least 1-12 inch thick, exte- 
riorly greenish-brown or yellowish-brown, more or less glossy, with trans- 
verse scars; inner surface light brown, sometimes striate or fissured. When 
dry it has a faint tan bark odor; when moistened it develops a decided odor 
of bitter almond. Taste astringent, bitter-almond like, and bitter. 

Contains tannin, amygdalitis emulsin, some resin, and the bitter principle 
prunin. When macerated with water the amygdalin decomposes and yields 
hydrocyanic acid and a volatile oil similar to that produced from bitter 
almond. 

It is a bitter tonic and slightly sedative. Mostly used for its agreeable 
flavor. 

Dose. — Fluid Ex:ract. 30 to 60 minims: Infusion. 1 to 3 fluid ounces; 
Syrup, about y z fl. oz. 

1 176. Quercus Alba. White Oak Bark. 
From Quercus alba (Cufiulifenz). 

The United States. 

Flattish pieces, about }{ inch thick, with corky layer removed; pale 
brown; with short ridges lengthwise on the inner surface: coarse fibrous 
fracture. A faint tan bark odor: taste very astringent. Usually coarsely 
ground. 

Contains tannin, called quercitannic acid, from 6 to 15 per cent. Used as 
an astringent. 

1177. Rhamnus Purshiana. Cascara Sagrada. 
The bark of Rhamnus Purshiana [Rhamnaceee). 

Rocky mountains and the Pacific slope. 

Thin, brittle troughs or quills of various lengths, externally brownish-gray- 
in younger bark, the brown is mettled with nearly black alternating with 



ABOUT DRUGS. 359 

whitish or ash-colored spots; yellowish-brown or orange-yellow on the inner 
side. Odor faint; taste bitter, disagreeable. 

Constituents similar to those of Frangula (1171). 

Purgative. 

Dose of Fluid Extract, 15 to 60 minims. 

1178. Rubus. Blackberry Root Bark. 

The bark of the root of Rubus villosus and Rubus trivialis (Ros- 
acea). 

The United States. 

Quills, troughs, or flexible bands, externally blackish-gray, inner surface 
light-brownish; inodorous, astringent, bitter. 

Contains tannin and is used as an 

Astringent. 

Dose of Fluid Extract, 1 to 2 fl. drs. 

1 179. Sassafras. Sassafras Bark. 

The root bark of Sassafras officinalis (Lauraceae). 

The United States and Canada. 

Irregular pieces deprived of the corky layer, bright rust brown, soft, brit- 
tle, with short fracture. Odor strongly aromatic; taste sweetish, aromatic, 
somewhat astringent. 

Contains about 3 per cent, volatile oil, some resin, and a little tannin. 
Used mainly as a flavoring constituent. 

1180. Ulmus. Slippery Elm Bark. 
The inner bark of Ulmus fulva (Urticacece.) 
The United States. 

Flat pieces, about }i inch thick, tough, pale brownish-white, fracture 
fibrous; odor faint, peculiar; taste insipid, mucilaginous. 
Contains mucilage. 
Demulcent. 

1181. Galla. Nutgall. 

Excrescent growths upon the bark of Quercus lusitanica, 
var. infectoria (Cupuliferce) caused by the punctures and deposits 
of ova made by the insect Cyuips Galla tinctorial. 

The Levant. 

Subglobular, about 1+ inch in diameter, tuberculated above; heavy, hard, 
dark olive-green or blackish-gray; fracture granular, grayish; nearly inodor- 
ous; taste, strongly astringent. 

Contains from 40 to 70 per cent, tannin, and 2 to 3 per cent, gallic acid. 

Powerfully astringent. 



360 ABOUT DRUGS. 

CHAPTER LXVI. 

HERBS, FLOWERS, AND LEAVES. 

1 182. Cannabis Indica. Indian Cannabis or Indian 
Hemp. 

Flowering tops of the female plant of Cannabis sativa ( Urti- 
cacece), grown in the East Indies. 

Branching, brittle, with small linear lanceolate leaflets, small pistillate 
flowers, and occasionally some hemp seed, the whole top resinous and sticky 
when warmed in the hand. Color greenish-brown; odor peculiar aromatic, 
narcotic; taste slightly acrid. 

Contains resin and volatile oil. 

Intoxicant. Hypnotic. 

Dose. — Extract, 3.6 to y 2 gr.; Fluid Extract, 2 to 5 minims; Tincture, 8 
to 30 minims. 

1183. Eupatorium. Boneset. 

The leaves and flowering tops of Eupatorium perfoliatu?n 
(Composite?). 

North America. 

Leaves opposite, united at the base, lanceolate, 4 to 6 inches long, rough 
on the upper side, downy beneath; flowers numerous, in corymbs, florets 
white; odor aromatic; taste bitter, astringent. 

Contains volatile oil, the bitter eupatorin. and a little tannin. 

Emetic, diaphoretic. 

Dose of Fluid Extract, 15 to 60 minims. 

1184. Grindelia. Grindelia Robusta. 

Flowering tops and leaves of Grindelia robusta (Compositce). 

West of the Rocky Mountains, especially in California. 

Leaves about two inches long, narrow, pale green, brittle; heads many- 
flowered, about one-half to three-fourth inches in diameter; flowers yellow, 
the whole top resinous; odor aromatic: taste pungent, aromatic, bitter. 

Contains volatile, oil and resin. 

Stimulant, diuretic. 

Dose of Fluid Extract, 30 to 60 minims. 

1185. Lobelia. Indian Tobacco. 

Leaves and tops of Lobelia inflata (Lobeliacece), collected after 
a portion of the capsules have become inflated. 
The United States. 



ABOUT DRUGS. 361 

Leaves alternate, oblong, about two inches long, pale green; flowers pale 
"blue; odor slight; taste acrid, nauseating. 

Active principle, the volatile alkaloid lobeline. 

Emetic, powerfully depressant, narcotic. 

Dose. — Vinegar of Lobelia, 15 to 60 minims; Fluid Extract, 3 to 30 
minims; Tincture, 10 to 45 minims. Much smaller doses are given when the 
drug is used as an expectorant. 

1186. Marrubium. Hoarhound. 

The leaves and tops of Marrubium vulgare (Labiatce). 

Europe and America. 

Leaves about one inch long, opposite, ovate, obtuse, downy above, hairy 
beneath, flowers white in whorls; odor slight, herbaceous; taste bitter, 
aromatic. 

1187. Mentha Piperita. Peppermint. 

The leaves and tops of Mentha piperita (Labiatce). 
Cultivated in North America and Europe. 

Leaves about 2 inches long, pointed, stems quadrangular, flowers small, 
purplish; odor peculiar, aromatic; taste pungent and cooling. 
Contains volatile oil. 
Stimulant. 

1188. Anthemis. Chamomile. 

The flower-heads of Anthemis nobilis (Composites), from culti- 
vated plants. 

Cultivated in Europe. 

Subglobular, about ^ inch broad, florets white; odor aromatic, peculiar. 
taste aromatic, bitter. 

Contains volatile oil. 

Stimulant. 

1189. Arnicae Flores. Arnica Flowers. 
The flower-heads of Arnica montana (Composite). 
Europe and North America. 

About i| inches broad, florets yellow, pappus hairy; odor feeble, aro- 
matic; taste bitter, acrid. 
Contains volatile oil. 
Used only externally. 

1190. Brayera. Koosso. 

The female inflorescence of Brayera anthelmintica (Rosacea). 
Abyssinia . 

Clusters of panicles of reddish flowers; odor feeble, tea-like, reminding of 
elder flowers; taste bitter, disagreeable, acrid. 



362 ABOUT DRUGS. 

Contains the bitter resinous principle Koossin. Anthelmintic. 
Dose. — Powder, 2 to 4 drachms; Fluid Extract, 1 to 4 fluid drachms; Infu- 
sion, one pint. 

1191. Caryophyllus. Cloves. 

The unexpanded flowers of Eugenia caryophyllata (Myrtacece) 

Africa. 

A little over y z inch long, consisting of a calyx mounted by four spread- 
ing sepals, surrounding the four petals which overlap each other forming 
a globular bud about A inch in diameter; color, rich brown; odor, strongly 
aromatic; taste, aromatic, pungent. Volatile oil exudes when the clove is 
scratched or indented by the nail. 

Contains from 15 to 20 per cent, volatile oil, which is the most valuable 
constituent. 

Aromatic and stimulant. 

1 192. Crocus. Saffron. 

The stigmas of Crocus sativus (Iridacea). 

Austria, Spain, France, Italy, etc. 

Separate, or three together attached to a portion of the style; the stigmas 
are thread-like, about 1% inch long, flattened and notched at the top, soft, 
flexible, of a rich orange brown color; odor, decided, peculiar, agreeable, aro- 
matic; taste, aromatic, bitterish. Colors the saliva a deep golden-yellow. 

Contains volatile oil as its most important constituent. 

Used as a flavoring ingredient and a coloring agent, but is stimulant and 
diuretic. 

Dose of the Tincture, 1 to 2 fluid drachms. 

1 193. Lavandula. Lavender. 

The flowers of Lavandula vera (Labiatce). 
Cultivated in Europe. 

Small, with tubular blue-gray calyx, violet-blue corolla; odor fragrant: taste 
bitterish, aromatic. 

Contains volatile oil. 

Stimulant, used mainly as an aromatizing ingredient. 

1 195. Rosa Gallica. Red Rose. 

The petals of Rosa gallica (Rosacea), collected just before the 
expansion of the roses. Cultivated in France. 

Roundish, deep purplish red petals of a rose-like fragrance; taste, bitter- 
ish, slightly acidulous, somewhat astringent. 

Contains a very small amount of volatile oil and a little tannin. 

Used as a mild astringent for children. 



ABOUT DRUGS. 365 

1104. Matricaria. German Ckamcvili. 
The never r.e^is ::' .*/ .".: _".- r.::.-..? 1. 

Eurcpe. 

Ar:_: - :r. :r. :r:a: rar--;re:s — i::e. f.~ — er= yell;-*-: :i;r arena::: 
taste, bitter, strongly aromatic 
Contains volatile oil. 
Used as a diaphoretic and stomachic. 

1 196. Sambucus. E:~ir Floti?.;. 

The f. :■ '.vers ::' i".:";h'. .":. : .-.: ?.:-": ■::.■: T.:r *•;'-".'. ';'.:. v..? . 
North America. 

5~a... :rea~-::' irei :: pale ye..:- :ie: ,.;;_'.. a: ar:~at:: :as:e 
erish arena::: 5:rr.e r.^.: ::::e: 
Contains -volatile oil and a little acrid resin 
5::rr.U-ar: ar. e ::apr.:re:::. 

1197. Santonica. Levantic Wormseed, or Germ an Worm- 

The unexpanded flower-heads of Artemisia maritima {Com- 
positce). 

Turkestan. 

arly -fV inch long, ovoid, grayish-green: odor strong, peculiar; taste 
aromatic, bitter. 

Con"a:r.£ the pe: itt'z'.y a::i pr:r:::ple .-'.-:.>;:».- are. s:~e r:'.a::'.e 

::'. ar 1 res r 

Anthelmintic. 

1198. Belladonnas Folia. Eiiiai::;na Liavis.— Frcm 

A:-\ r.z -?:■.".".:-'."'."■'.•■- • o.. ".::.:.:.: . 

Central and southern Europe. 

Four to 6 inches long, broadly ovate, tapering, smooth, thin, brownish- 
rreer a"::ve gray:;r. greer. zer.ea;.r. :i:r :a:r: r7::a:e:_s :as:e "e:::er;si 
■_:.: easar: 

Active principles.— T'-^ - ar.d 

rial : anodyne.:: 35 

Dose. — Extract, \ to \ grain Fluid Extract .: 5 rr.:r.:rr.= Tinctnie 15 
to 30 minims. 

Poisonous Effects :r.r. Antidotes.— See 1:5 = 

1109. Buchu. Buchu Leaves. — From Barosma betulina.B, 
crcnulata, and B. serntifolia {Rut<ice<z). 

5:u:herr. Africa- 



364 ABOUT DRUGS. 

There are two recognized varieties of the drug : Long 
Buchu from B. betulina, and B. crenulata, and short buchu from 
B. s err at 1 ; folia. 

Long buchu consists of narrow, lanceolate leaves, about one inch long, 
thin, green. 

Short buchu consists of leaves about f inch long, roundish oval, 
obtuse, thickish, pale green. 

Both kinds of leaves have serrate or crenate edges, are strongly aromatic 
and have a strong, pungent, bitterish taste, somewhat reminding of mint. 

Contains volatile oil, which is the only active constituent. Mucilage is 
also contained in the drug. 

Used as an aromatic stimulant and diuretic. 

Dose of the Fluid Extract, 15 to 30 minims. 

1200. Digitalis. Foxglove . 

The leaves of Digitalis purpurea (Scrop/iulariacece) collected 
from plants of the second year's growth. 

Europe. 

Leaves 4 to 12 inches iong; oblong, crenate, wrinkled, coarsely net- 
veined, downy on the under side, mid-rib thick; dull green above, paler 
beneath; odor feeble; herbaceous; taste bitter, disagreeable. 

Active Principles. — The principal active constituent is iigitoxin. Digi- 
talis is a heart stimulant and a diuretic. 

Dose. — Powder, y 2 to 10 grains; Abstract, 1 to 2 grains; Extract, \ to 4- 
grain; Fluid Extract, 3 to 15 minims; Infusion, 2 to 6 fluid drachms; Tincture, 
5 to 60 minims. 

Poisonous Effects. — In large doses it may cause a too powerful contrac- 
tion of the heart, or tetanic spasm. Or the excitement of the heart produced 
by the drug may be followed by fatal exhaustion. Headache, dizziness, 
delirium, exhaustion, are among the symptoms of poisoning by digitalis. 

Antidotes. — Opium, aconite, saponin, etc. Stimulants are given to coun- 
teract depression. 

1201. Erythroxylon. Coca Leaves. — From Erythroxylon 
Coca (Erythroxy lacecs). 

Peru. 

Oval, 2 or 3 inches long, pale green, net-veined, vith prominent mid-rib, 
and a curved line from base to apex on each side of tie mid-rib; odor feeble, 
herbaceous; taste bitterish, slightly aromatic. 

Active principle. — The alkaloid cocaine. 

Stimulant. 

Dose of Fluid Extract, 1 to 4 fluid drachms. 



ABOUT DRV - 365 

1202. Eucalyptus. Eucalyptus. 

The leaves of Eucalyptus globulus [Myrtaceaz\ collected from 
rather old trees. 

Australia. Cultivated in California. 

Scythe-shaped, from 6 to 12 inches long, tapering, thick, grav-green. 
feather-veined; odor, camphoraceous. strong: taste, pungent, aromatic, bit- 
terish, a little astringent. 

Contains volatile oil and resin. 

S::mulant. diaphoretic, antiseptic, limnetic 

Dose of the Fluid Extract, 15 to 60 minims. 

1203. Hyoscyamus. Henbane. 

Leaves of Hyoscyamus iriger {Solanacea) collected from plants 
of the second year's growth. 
Europe. 

Oblong, from 4 to 10 inches long and 2 to 4 inches broad, soft, hairy, 
glandulous, wrinkled: have a broad, whitish, prominent mid-rib; grayish- 
green; odor strong, narcotic; taste bitter, acrid. 

Active principles. — The alkaloids hyoscyav.: vscitu. ■ 

Anodyne, hynotic, narcotic. 

Dose. — Abstract. 2 to 6 grains; Extract, 1 to 2 grains: Fluid Extract. 5 to 
30 minims: Tincture. 15 minims to 2 fl. drs. 

Poisonous Effects similar to those of belladonna (11351, and antidotes 
the same. 

1204. Matico. Matico. 

The leaves of Arthante clongata (Piperacece). 

South America. 

They are 4 to 6 inches long, about an inch or more broad, pointed, vena- 
tion very prominent on the under side, upper surface wrinkled: brittle, hairy; 
odor, aromatic, spicy; taste, pungent, bitterish, astringent. 

Contains volatile oil and resin, and a little tannin. 

?::mulant, blennhoretic. diuretic. 

Dose. — Fluid Extract, 30 to 60 minims: Tincture, 1 to 4 fluid drachms. 

1205. Pilocarpus. Jaeorandi. 
The leaves of Pilocarpus pinnatifolius (Rutacca). 
Brazil. 

About 4 inches long, oblong, obtuse, thick, grayish-green, smoothish: 
slightly aromatic when rubbed: bitter, somewhat pungent. 
Contains the alkaloids pilocarpine and jat ore ndine. 
Powerful diaphoretic. 
Dose of the Fluid Extract. 30 to 120 minims. 



366 ABOUT DRUGS. 

1206. Rosmarinus. Rosemary. 
From Rosmarinus officinalis (Labiatai). 
Cultivated in Europe. 
Almost needle-shaped, about an inch long, dark green, strongly aromatic, 

pungent. 

Contains volatile oil. 
Stimulant. Rarely used. 

1207. Salvia. Sage. 

From Salvia officinalis (Labiatce). Cultivated. 
About 1 to 2 inches long, oval, wrinkled, thick, soft, hairy, grayish-green; 

aromatic, bitterish, somewhat astringent. 
Contains volatile oil and a little tannin. 
Stimulant, slightly astringent. Used in gargles. 

1208. Senna. Senna. 
There are two varieties: 
Alexandria Senna consists of the leaflets of Senna acutifolia 

\Le gummosa?) . 

Africa. 

About 1 inch long and y$ inch broad across the middle, pointed, thick, 
smooth, brittle, grayish-green; odor peculiar, nauseous; taste nauseous, bit- 
terish. 

India Senna consists of the leaflets of Cassia elongata. 

India; cultivated. 

About 2 inches long, \ inch broad, pointed, not thick, dull green (darker 
than the Alexandria Senna), not brittle; odor about the same as of the other 
variety of senna; taste mucilaginous, bitter, nauseous. 

Senna should be free from stalks and other admixtures. 

Contains cathartin, chrysophan, and other less important constituents. 

Cathartic. 

Dose. — Powder, 30 to 150 grains; Confection, 60 to 150 grains; Fluid 
Extract, 1 to 4 fluid drachms; Compound Infusion, 1 to 3 fluid ounces; Syrup, 
1 to 4 fluid drachms. 

1209. Stramonium. Stinkweed; Jimpson Weed. 
From Datura Stramonium (Solanacece). 
North America as well as Europe. 
About 6 inches long, 4 inches broad, one-third of their length from the 

base, unsymmetrical in outline and venation, wrinkled, thin, brittle; develop 
a disagreeable narcotic odor when rubbed; taste, bitter, nauseous. 
Contains the alkaloids atropine and hyxcyamine. 



ABOUT DRUGS. 367 

Narcotic, anodyne, hypnotic. Effects similar to those of belladonna 
{1135) and hyoscyamus (1203). 

1210. Tabacum. Tobacco. 
From Nicotiana Tabacum (Solanacece). 

Cultivated in the middle Southern States of the United 
States, and in Cuba, etc. 

Up to 20 inches long, oval, lanceolate, pointed, brown, brittle, hairy; 
odor, peculiar, strong, nauseous, narcotic; taste, nauseous, bitter, acrid. 

Contains the poisonous volatile alkaloid nicotine. 

Used only externally, being too dangerous for internal administration. 
Depressant. 

1211. Uva Ursi. Bearberry Leaves. 
From Arctostaphylos Uva-ursi {Erica cece). 
Northern Europe and America. 

About four-fifths inch long, y z inch broad, obovate, thick, smooth, glossy, 
dark green above, paler beneath, odor hearbaceous; taste very astringent, 
somewhat bitter. 

Contains tannin, and some gallic acid, besides certain peculiar principles 
called arbutin, ericolin, and tirsone. 

Astringent, diuretic. 



CHAPTER LXVII. 



fruits and seeds. 

1212. Anisum. Anise. 

The fruit of Pimpinella Anisum (Umbellifer<z). 
Cultivated in Germany, Italy and other countries. 
About 14 inch long, ovate, greenish-gray, fine-hairy, ridged; odor, agree- 
able, aromatic; taste, aromatic, sweet, pungent. 
Contains volatile oil. 
Stimulant, carminative. Much employed for flavoring. 

1213. Capsicum. Cayenne Pepper. Red Pepper. Afri- 
can Pepper. 

The fruit of Capsicu?n fastigiatum (Solanacece). 
Africa, South America. 



368 ABOUT DRUGS. 

Oblong, about % to ^ inch long, glossy, red membranous capsules, con- 
taining flat yellowish seeds. Odor, peculiar; taste, fiery, acrid. 

Contains the volatile, acrid "principle capsaicin together with volatile oil 
and acrid resin. 

Used as a stimulant, carminative; externally as a counter-irritant and 
rubefacient. 

Dose. — Fluid Extract, 3 to 8 minims; Oleoresin, l /% to l /$ minim; Tinc- 
ture, y 2 to 1 fluid drachm. 

Externally are used the Capsicum Plaster, and also the Oleoresin. 

1214. Cardamomum. Cardamom. 

The fruit of Elettaria Cardamomum {Zingiber acecK). 

Malabar, etc. 

Ovoid, about % inch long, ^ to y$ inch in diameter, triangular; pale 
buff, leathery pericarp. Seeds dark reddish-brown, very small, hard; odor, 
peculiar, agreeable, aromatic; taste, aromatic, pungent. 

Contains volatile oil. 

An aromatic stimulant and carminative. Much used for flavoring. 

1215. Carum. Caraway. 

The fruit of Carum Carvi {Umbelliferoz). 
Cultivated in Europe. 

Slender, oblong, about Ye inch long, dark brown; odor agreeable, aro- 
matic; taste, sweetish, aromatic, pungent. 
Contains volatile oil. 
A stimulant, carminative, stomachic. Much used for flavoring. 

1216. Chenopodium. American Wormseed. 
The fruit of Chenopodium ambrosioides {Chenopodiacece) . 
Europe and North America. 

Nearly globular, about T ^ inch in diameter, dull brownish-green; odor 
strong, peculiar, disagreeable; taste bitterish, pungent, nauseous. 
Contains volatile oil. 
Anthelmintic. 
Dose. — 15 to 30 grains. 

1217. Colocynthis. Colocynth. 

The fruit of Citrullus Colocynthis {Cucurbitaceoe), deprived of 
the rind. 

Spain, Western Asia. 

Globular, from 2 to 3 inches in diameter, white or yellowish-white; light, 
porous, brittle, containing a large number of flat, brownish seeds; inodorous; 
taste extremely bitter. 



ABOUT DRUGS. 369 

The seeds, which constitute three-fourths by weight of the drug, are 
rejected in making preparations. 

Contains the bitter cathartic principle colocynihin; also resin. 

Used as a cathartic. 

Dose of powder, 5 to 10 grains; Extract, 1 to 1^ grains; Compound 
Extract, 4 to 8 grains; Fluid Extract, 4 to 8 minims. 

1218. Conium. Hemlock. 

The full grown fruit of Conium maculatum (Umbelliferce), 
gathered while yet green. 

Europe, North America. 

About l /% inch long, oval, gray-green; odor feeble but disagreeable; taste 
bitterish, slightly acrid. When triturated with potassa solution it gives off a 
pronounced, offensive odor. 

Contains the poisonous volatile alkaloid coniine. 

Sedative, narcotic. 

Dose. — Abstract, 1 to 3 grains; Extract, ^toi grain; Fluid Extract, 2 
to 5 minims; Tincture, 15 to 60 minims. 

Poisonous Effects. — Nausea, vomiting, disturbed vision, dizziness, 
numbness, paralysis, asphyxia. 

Antidotes. — Enforced strong muscular exercise; the administration of 
nux vomica or strychnine. 

1219. Coriandrum Coriander. 

The fruit of Coriandrum sativum (Umbelliferce). 
Southern Europe. Cultivated. 

Globular, about \ inch or less in diameter, slightly ridged, brownish- 
yellow; odor and taste peculiar, agreeable, aromatic. 
Contains volatile oil. 
Aromatic, stimulant, carminative. Chiefly employed for flavoring. 

1220. Cubeba. Cubeb. 

The unripe fruit of Cubeba officinalis (Piperacece). 

Java. Cultivated. 

Globular, of about the size of black pepper, dark grayish-brown, wrinkled 
on the surface; interiorly light colored"; odor strong, aromatic; taste pungent, 
aromatic, bitter. 

Contains volatile oil and resin, and the crystallizable, inactive neutral 
principle called cubebin. 

Stimulant, diuretic. 

Dose. — Powder, 10 to 60 grains; Fluid Extract, 15 to 30 minims; Oleo- 
resin, 5 to 10 grains; Tincture, \ to 2 fluid-drachms. 



37° ABOUT DRUGS. 

1221. FoeniCUlum. Fennel. 

The fruit of Foeniculum vulgar e {Umbelliferce). 
Europe. Cultivated. 

About \ inch long, oblong, nearly cylindrical, slightly curved, greenish- 
brown, ribbed; odor and taste sweetish, aromatic, anise-like. 
Contains volatile oil. 
Stimulant, carminative. 

1222. Humulus. Hops. 

The strobiles (or fruit cones) of Humulus Lupul us (Urticacece). 

Cultivated. 

About an inch long, yellowish-green cones; odor peculiar, aromatic; 
taste bitter, aromatic. 

Constituents. Lupulin (1224.) containing volatile oil and resin; hops also 
contain a little tannin. 

Bitter, tonic, stomachic. 

Dose of Tincture, 1 to 2 fluid drachms. 

1223. Juniperus. Juniper Berries. 

The ripe fruit of Juniperus communis (Coniferce) . 

Northern countries. 

Nearly globular, about l /£ inch in diameter, dark purplish black with a 
bluish-gray bloom, fleshy, interiorly greenish brown; odor, aromatic, terebin- 
thinate; taste, sweet, bitterish, pungent. 

Contains volatile oil, resin, and sugar. 

Stimulant and diuretic. 

1224. Kamala. Kamala . 

The glands and hairs from the capsules of Mallotus philip- 
pinensis (Euphorbiacece) . 

India, Arabia. 

A fine granular, brown-red powder, inodorous, tasteless, insoluble in 
water; imparting a deep red color to alcohol, ether, chloroform and alkaline 
solutions. 

Contains nearly 80 per cent, of alcohol-soluble resin. Yellow, needle- 
like crystals of rottlerin deposit from a concentrated ether solution. 

Dose, as a tcenicide, from 1 to 2 drachms. 

1225. Lupulinum. Lupulin. 

A glandular powder separated from hops (1222). 
Coarse, orange brown or brownish-yellow, resinous, aromatic, bitter. 
Ether dissolves about three-fourths of it. 
Contains volatile oil and resin. 



ABOUT DRUGS. 371 

Tonic, stomachic. 

Dose. — Fluid Extract, 5 to 15 minims; Oleoresin, 2 to 4 grains; Tincture, 
% to 2 fluid drachms. 

1226. Piper. Black Pepper. 

The unripe fruit of Piper nigrum (Piperacece). 

India. 

Globular, about \ inch in diameter, much wrinkled, brownish-black or 
grayish-black, interiorly lighter, hollow; odor, peculiar, spicy; taste, spicy, 
hot. 

Contains volatile oil, resin, and the feebly alkaloidal principle piperine. 

Stimulant, carminative. 

Dose of the Oleoresin % to 1 grain. 

1227. Vanilla. Vanilla Bean. 

The fruit of Vanilla planifolia (Orchidacecs.) 

Mexico; cultivated. 

From 6 to 10 inches long, about ^ to ^ inch thick, much wrinkled, flexible, 
dark brown, glossy containing a blackish-brown oily-looking pulp. Odor, 
peculiar, heavy, very fragrant; taste, agreeably aromatic. 

Contains the crystallizable fragrant principle vanillin, or vanillic acid. 
Used for flavoring. 

1228. Amygdala. Almond. 

Sweet almond and bitter almond are both seeds of Amygdalus 
communis (Rosacea): but sweet almond is obtained from the 
variety called dulcis, and the bitter almond from the variety 
called amara. 

Both varieties of almond contain fixed oil (" sweet oil of almond "). Bit- 
ter almond contains also the crystallizable, bitter glucoside amygdalin, which 
decomposes when the almond is moistened, yielding hydrocyanic acid and 
volatile oil of bitter almond. 

1229. Colchici Semen. Colchicum Seed. 
The seed of Colchicum autumnale (Melanthacece). 
Europe. 

Subglobular, about ^ inch in diameter, hard, tough, reddish-brown, 
interiorly whitish; inodorous; bitter, acrid. 
Contains the alkaloid colchicine. 
Alterative and diuretic, in gout. 

Dose. — Fluid Extract, 2 to 5 minims; Tincture and Wine, 10 to 30 minims. 
Poisonous Effects and Antidotes. — See Colchicum Root (1139). 



37 2 ABOUT DRUGS. 

1230. Cydonium, Quince Seed. 
The seed of Cydonia vulgaris {Rosaceoe). 
Cultivated. 

About % inch long, oval or oblong, compressed, dark brown, covered 
with a whitish, mucilaginous film, soluble in water. 

Contains mucilage on the surface of the seed-coat. 

1231. Linum. Flaxseed. 

The seed of Linum usitatissimum {Linacece). 
Cultivated. 

About \ inch long, oblong, ovate, flattened, pointed at one end, brown, 
glossy, covered with a water-soluble vegetable mucilage. 

Contains mucilage (on the surface of the seed-coat) and fixed oil. 

1232. Myristica. Nutmeg. 

The seed of Myristica fragrdns (Myristicacece) deprived of its 
testa. 

India, the Philippines, Banda Islands, West Indies, South 
America. 

Oval, about 1 inch long, light brown, furrowed, interiorly pale brownish, 
with darker veins and greasy; strongly aromatic, pungent, bitter. 

Contains volatile oil and fixed oil. 

Stimulant, carminative. 

1233. Nux Vomica. Nux Vomica. 

The seed of Strychnos Nux-vomica (Loganiacece). 

East Indies. 

Circular disks about 1 inch in diameter, % inch thick, grayish or green- 
ish-gray, with a silky lustre from soft hairs, hard, interiorly grayish-white, 
horny, tough, inodorous, intensely and persistently bitter. 

Contains the extremely poisonous alkaloids strychnine and brucine . 

Motor excitant; tonic. 

Dose. — Abstract, y z to 2 grs.; Extract, % to 1 gr. ; Fluid Extract, 1 to 5 
minims; Tincture, 5 to 20 minims. 

1234. Physostigma. Calabar Bean. 

The seed of Physostigma venenosum (Leguminosce). 

Western Africa. 

Roundish, oblong, about 1 inch long, ^ inch broad and l / 2 inch thick, 
one long edge straight, the other convex, chocolate brown, with a black groove 
along the convex edge, interiorly white, fleshy; inodorous; taste, bean-like. 
The white color of the embryo turns pale yellow on being moistened with solu- 
tion of potassa. 



ABOUT DRUGS. 



373 



Active principle, the alkaloid physostigmine, also called " eserine;" it also 
contains another alkaloid called calabarine. 

A motor depressant; extremely poisonous. 

Dose. — Extract, 1-16 to l /e grain; Fluid Extract, 1 to 3 minims; Tincture, 
15 to 30 minims. 

Poisonous effects. — Extreme weakness, vomiting, feeble and slow pulse, 
collapse, death. 

Antidotes. — After evacuation of the stomach and bowels, atropine is used 
hypodermatically. 

1235 Sinapis. Mustard. 

Two kinds of mustard are official — white and black. 

White Mustard is the seed of Sinapis alba [Cruciferce). 

Globular, about 1-12 inch in diameter, pale brownish-yellow, hard; pow- 
der bright yellow; inodorous; pungent, acrid. 

Black Mustard is the seed of Sinapis nigra. 

Globular, about 1-24 inch in diameter, hard, blackish-brown; inodorous; 
pungent, acrid. 

Both kinds of mustard are cultivated in Europe and America. 

Constituents. — Mustard contains from 20 to 25 percent, fixed oil. When 
moistened it emits a strong irritating odor, due to the " volatile oil of mus- 
tard " which is formed when water is added. 

Mustard is a rubefacient. 

1236. Stramonii Semen. Stramonium Seed. 

The seed of Datura Stramonium (Solanacece). 

North America and Europe. 

Reniform, about l /(> inch long, flattened, wrinkled, hard, brownish-black, 
interiorly whitish, oily; inodorous when whole, but emitting a disagreeable 
odor when bruised; taste bitter. 

Contains the alkaloids atropine and hyoscy amine; also fixed oils. 

Mydriatic anodyne. 

Dose. — Extract, about \ grain; Fluid Extract, 1 to 3 minims; Tincture, 
8 to 30 minims. 

It is also used externally in the form of ointment. 



374 ABOUT DRUGS. 

CHAPTER LXVIII. 

MISCELLANEOUS CRUDE PLANT DRUGS. 

Chondrus and Ergot. 

1237. Chondrus. Irish Moss; Carrageen. 

Consists of Chondrus crispus and C. mamillosus (A/gce). 

Tough, translucent, pale yellowish-white, branched; soft, slippery, carti- 
laginous-looking when put in water; boiled with from 20 to 30 parts of water r 
it forms, on cooling, a jelly of a mucilaginous taste and a distinct sea-weed 
odor. 

Contains pectin 
Demulcent. 

1238. Ergota. Ergot; Secale Cornutum. 

The sclerotium (compact spawn) or middle (second) stage 
of development of the fungus Claviceps purpurea {Fungi), which 
grows within the flower of the common rye, taking the place 
of the grain. 

Southern Europe, especially Spain and Southern Russia. 

Grain-like bodies about 1 to 2 inches long, | to \ inch thick, nearly trian- 
gular, somewhat curved, marked lengthwise by three grooves, that on the 
inner side of the curve being most distinct; thickest about the middle, taper- 
ing gradually toward both ends, which are blunt; externally dark purplish, 
with a slight cloudy, bluish bloom; plump, firm, somewhat elastic but easily- 
broken; fracture even, whitish toward the center but pinkish toward the cir- 
cumference; fissured when old; odor peculiar, heavy, disagreeable; taste, 
greasy, mawkish, nauseous. 

When ergot is triturated with solution of potassium hydrate, a strong 
odor resembling that of herring brine (from trimethylamine) is developed. 

Contains, according to Dragendorff and Podwissotzky, scleretic acid, 
scleromucin and sclererythrin , all of which are brown amorphous powders hav- 
ing the medicinal properties of the ergot. 

Kobert produced the alkaloid comutine from ergot; this, also, has the 
active properties of the drug in a high degree. 

Ergot also contains 30 per cent, of fixed oil. 

Uses. — Ergot is a motor excitant and causes contraction of the unstriped 
or involuntary muscular fibres, as of the uterus, sphincters and arterioles. 

Dose. — Powder, 15 grains to 1 ounce; Extract, 5 to 10 grains; Fluid 
Extract, 1 to 16 fluid drachms. 



ABOUT DRUGS. 375 

Extract-like Drugs. 

1239. Aloe. Aloes; Socotrine Aloes. 

The inspissated juice of the leaves of Aloe socotrina (Liliacece). 

Eastern Africa and islands in the Indian Ocean. 

Reddish-brown or orange-brown mosses, with a somewhat resinous, dull, 
opaque, conchoidal fracture; in quite thin fragments it is translucent, with a 
garnet-red or brownish-red color; the powder is yellowish-brown. Soluble in 
four times its weight of boiling water. It exhibits numerous crystals of aloin 
when mixed with alcohol and then examined under the microscope. Odor, 
saffron-like, fragrant, intensified when the aloes is breathed upon. Taste, 
extremely bitter. 

Contains the bitter, purgative, resinous, neutral principle aloin and also 
a minute amount of volatile oil. 

Properties. — Purgative; in smaller doses, laxative; in minute doses, a 
bitter, stomachic tonic. 

Preparations and Doses. — Purified Aloes, in powder, as a tonic, 1 to 2 
grs.; laxative, 2 to 5 grs.; purgative, 5 to 15 grs. Extract, ]/ 2 to 5 grs.; Tinc- 
ture, 1 to 4 fluid drachms; Wine, about 4 fl. drs. 

1240. Catechu. Catechu; Cutch. 

An extract prepared from the wood of Acacia Catechu (Legu- 
minosce). 

Pegu, and most parts of India and Burmah. 

Dark-brown, brittle, irregular masses, somewhat glossy when freshly 
broken; soluble in water and in diluted alcohol; nearly inodorous; of strongly 
astringent, sweetish taste. 

Contains catechu-tannic acid and catechin. 

Astringent. 

Dose. — Powder, 1 to 30 grains; Compound Tincture, 10 to 60 minims. 

1241. Guarana. Guarana. 

A dried paste prepared from the seeds of Paullinia sorbilis 
(SapindacecE). 

Brazil. 

Cylindrical sticks, sometimes flattened, about 6 inches long and 1 inch 
in diameter, hard, externally dark-red brown, usually comparatively smooth, 
fracture uneven, coarsely granular, yet somewhat glossy, much lighter than 
the exterior. Odor, feeble, but peculiar, somewhat chocolate-like; taste, bit- 
ter, astringent. Guarana is partially soluble in alcohol, and also in water, 
the solutions being brown. 



37^ ABOUT DRUGS. 

Constituents. — The alkaloid gnaranine (probably identical with theine), 
and a large percentage of tannin. 

Properties. — Guarana resembles tea and coffee in its action, being a car- 
diac stimulant. 

Dose. — Powder, 10 to 60 grains; Fluid Extract, 10 to 60 minims. 

1242. Kino. Kino. 

The inspissated juice of Pterocarpus Marsupium (Leguminosee). 

India. 

Small, irregular, brittle, shining, dark, brown-red fragments, ruby-red 
and transparent in thin splinters. Colors the saliva deep-red; scarcely at all 
soluble in cold water, but almost entirely soluble in diluted alcohol; nearly 
insoluble in ether. Inodorous; very astringent, sweetish. 

Contains kino-tannic acid. 

Astringent. 

Dose. — Powder, 10 to 20 grains; Tincture, x / z to 2 fluid drachms. 

1243. Lactucarium. Lactucarium. 

The hardened milk-juice of Lactuca virosa (Composites). 

Europe 

In pieces showing the form of the vessel in which the juice was collected 
to harden. Often broken into irregular fragments. Exteriorly grayish-brown 
or dull reddish-brown, interiorly whitish or yellowish, waxy. Odor heavy, 
reminding somewhat of opium; taste, strongly bitter. 

Partially soluble in alcohol and ether; yields a turbid mixture when tritu- 
rated with water. 

Contains bitter lactucin, which is its only important constituent. 

Anodyne, soporific, hypnotic. 

Dose. — 8 to 30 grains; Fluid Extract, 5 to 30 minims; syrup, 2 to 3 fluid 
drachms. 

1244. Opium. Opium. 

The concreted, milky exudation obtained in Asia Minor by- 
wounding the unripe capsules of Papaver som?iiferum (Papaver- 
aeeee) y and yielding in its normal soft condition not less than 9 
per cent, of the alkaloid morphine when assayed by the official 
process. 

Powdered Opium, which is opium dried at not over 85. ° C. 
(185. ° F.) and reduced to No. 50 powder, is required to yield 
not less than 12, nor more than 16, per cent, of morphine. 

Crude opium, or whole opium, occurs in irregular sub-globular or flattened 
masses, with remains of poppy leaves and rumex seeds adhering to the sur- 



ABOUT DRUGS. 377 

face; moist enough to be soft or plastic, or so dry as not to flatten out when 
lying on a flat support. It is dark-brown, somewhat glossy when dry. 
The odor is peculiar, narcotic, nauseous; taste, bitter, disagreeable. 

When dried the normal opium, or "lump opium," as imported, loses 
from ten to twenty per cent, of moisture. 

When opium is dried at about 105 C. ( 221° F.) and then weighed and 
afterwards exhausted with cold water, the liquid water extracts being evapo- 
rated to dryness, the dry extract obtained should amount to from 55 to 60 per 
cent, of the weight of the dried opium taken. 

Whole opium is used for making powdered opium and extract of opium, 
but all other opium preparations must be made from dry " powdered opium." 

Active Principles. — The alkaloids morphine and codeine are the most 
valuable. 

Properties. — Opium is a hypnotic. It is a powerful narcotic, often 
employed to relieve pain as well as to produce sleep, etc. 

Dose. — Powders, about 1 grain; Extract, about ]/ 2 grain; Tinctures, 
about 10 minims; Vinegar, 5 to 10 minims; Wine, about 10 minims. 

Compound Preparations. — Troches of Glycyrrhiza and Opium; Powder 
of Ipecac and Opium, or Dover's Powder, of which the adult dose is about 10 
grains; Tincture of Ipecac and Opium, about 10 minims; Camphorated Tinc- 
ture of Opium, of which the dose is about 2 to 4 fluid drachms. 

A Plaster of Opium is also official. 

Denarcotized Opium and Deodorized Tincture of Opium are contained 
in the Pharmacopoeia. They are comparatively free from the alkaloid narco- 
tine, which is considered an objectionable constituent, and from the nauseous 
odor. 

Pills of Opium are also official. 

All opium preparations of the United States Pharmacopoeia, for internal 
use, are of 10 per cent, strength, w'ith the sole exception of the Camphorated 
Tincture of Opium (" Paregoric "). 

Poisonous Effects. — Drowsiness, profound lethargy, breathing labored, 
slow and stertorous; face dusky and swollen; pupils contracted; heart's 
action slow and feeble; total relaxation, coma, death from paralysis of the 
respiratory muscles. 

Antidotes. — Prompt evacuation of the stomach by emetics or the stom- 
ach pump; then the patient should be compelled, if possible, to walk about, 
and the enforced exercise kept up; external stimulation, by rubbing, etc.; 
alcoholic stimulants, strong coffee; artificial respiration, if possible; and the 
administration of belladonna or atropine, or subcutaneous injections of atro- 
pine. • 



378 ABOUT DRUGS. 

CHAPTER LXIX. 

STARCHES. GUMS AND SUGARS. 

1245. Amylum. Starch. Wheat Starch. 

The fecula or starch of the seed of Triticui?i vulgar e (Gramin- 
acea),or wheat. 

Manufactured in all countries from cultivated wheat. 

Irregular, angular, soft, friable, white masses; inodorous and tasteless. 
Insoluble in cold water, alcohol and ether. 

1246. Maranta. Arrow-root. 

The fecula separated from the rhizome of Maranta arundina- 
cea (Cannacem). 

Bermudas, West Indies, Central and South America. 
Used for preparing foods for infants and invalids. 

1247. Acacia. Gum Arabic 

The dried gummy exudation from Acacia Verek and other 
species of Acacia (Leguminosce). 

Africa. 

Irregularly-shaped fragments or tears, opaque from numerous tissues, 
glass-like in the fracture, transparent in thin pieces; nearly inodorous; taste 
mucilaginous, insipid. Entirely soluble in water; insoluble in alcohol. 

Used in powder as an emulsifying agent and as an excipient; also in the 
form of mucilage for the same and other similar purposes, and as a demulcent. 

1248. Tragacantha. Tragacanth. 

The dried gummy exudation from Astragalus gummifer and 
other species of Astragalus (Leguminosce), 

Western Asia. 

Irregular, contorted bands, whitish, translucent, horn-like, tough, swell- 
ing in water to a gelatinous, sticky mass. 

Used as an excipient either in powder or in the form of mucilage of traga- 
canth. 

1249. Saccharum. Sugar. 

The refined sugar (C^H^Ou) of Saccharum offici?iaru?n (Grami- 
nacece). 

The Pharmacopoeia defines sugar as cane-sugar, only; but most of the 
white sugar now consists of beet-root sugar. 

Sugar is soluble in about half its weight of water at 15° C; it is also- 
soluble in 175 parts of alcohol at 15° C, but insoluble in ether. 






ABOUT DRUGS. 379 

1250. Saccharum Lactis. Milk Sugar. 

This variety of sugar (Cx2H2.2Ou.H2O) is obtained from the 
whey of cow's milk. 

Hard, crystalline, white, inodorous, sweetish, soluble in 7 times its weight 
of water at I5 C C. 

Used as a diluent in powders, triturations, and in various tablets, gran- 
ules, etc. 

1251. Manna. Manna. 

The concreted saccharine exudation from Fraxinus Or?ius^ 
{Oh ace a). 

Southern Europe. 

Flattish, trough-shaped or three-edged pieces, friable, yellowish-white, 
porous crystalline; odor peculiar, sweetish; taste sweet, leaving a slightly 
bitter, acrid after-taste. Water-soluble, and soluble also in 15 parts of boiling 
alcohol. 

Consists mainly of mannit and glucose. 

Used as a mild laxative. 

1252. Mel. Honey. 

A saccharine secretion deposited by the bee. Apis mellifica 
{Insccta). 

Syrupy, or semi-fluid and granular, pale-yellow or brownish-yellow, of a 
peculiar sweetish odor; very sweet, afterwards faintly acrid taste. When heated, 
skimmed and strained, it is called clarified honey, which is used in the prepara- 
tion of confection of rose, honev of rose, and in mass of carbonate of iron. 



CHAPTER LXX. 



GUM-RESINS, RESINS, AND BALSAMS. 

1253. Ammoniacum. Ammoniac. 

A gum-resin (1123) obtained from Dorema Apimoniacinn (Um- 
belliferce). 

Persia, Turkestan. 

Roundish tears of various sizes rarely exceeding an inch in diameter, pale 
brownish-yellow exteriorly, white interiorly, brittle only when cold, fracture 



5i3 ABOUT DRUGS. 

waxy and conchoidal; odor peculiar; taste bitter, acrid, disagreeable. Yields 

a milk-white emulsion when triturated with water. 
Contains volatile oil, resin and gum. 

Antispasmodic and blennorhetic. Externally a stimulant and rubefa 
Preparations. — Mixture of Ammoniac, and for external use the Ammoniac 

Plaster with or without mercury 

1254. Asafoetida. Asafetida. 

A gum-resin obtained from the root of Ferula Narthex and 
F. Scorodosma \UmbdliferiE). 

Persia, and other countries on the Arabian Sea. 

Tears, exteriorly brown, interiorly white, or masses composed of such 
tears imbedded in a yellowish-brown soft or hard mass. When hard the tears 
break with a conchoidal wax} T fracture, the milk-white color of the surface of 
the fracture changes gradually on exposure to the air to pink and brown. 
O::: string garlicky, ozer.sive: taste bitter, acrid, garlicky. Wit en triturated 
with water it yields a nearly milk-white emulsion. At least 60 per cent, of the 
asafetida should be dissolved by alcohol. 

Contains volatile oil, resin and gum. 

Used as a nervine and antispasmodic, and also externally as a stimulant 
application in the form of plaster. 

Preparations. — Mixture (dose, 4 fluid drachms), Tincture lose, 30 to 60 
minims), Pills of Asafetida, Pills of Aloes and Asafetida, Compound Pills :: 
Galbanum. Asafetida Plaster. 

1255. Galbanum. Galbanum. 

The gum-resinous exudation from Ferula galbaniflua, and 

probably from other related plants ( Umbelliferce). 

Persia. 

Masses consisting of small agglutinated tears, exteriorly yellowish-brown, 
interitrly whitish, fracture waxy; tier ceculiar, disagreeable; taste bitter, 
acrid. 

Contains volatile :il, resin and gum. 

Stimulant, blennorrhetic, externally stimulant. 

Preparations. — Galbanum Plaster, Compound Pills of Galbanum, and in 
Asafetida Plaster, 

1256. Cambogia. Gamboge. 

A gum-resin from Garcima Hanburii | Guttife^a). 

Siam. 

Cylindrical pieces, from ?+ to 2 inches in diameter, brownish orange- 
yellow; fracture smooth, waxy; powder bright yellow; inodorous; acrid. 
Triturated with water it yields a yellow emulsion. 



ABOUT DRUGS. $8l 

Contains resinous gambogic acid and gum. 

It is a powerful hydrago^ue cathartic (dose, 1 to 5 grains) and is contained 
in Compound Cathartic Pills. 

1257. Myrrha. Myrrh. 

A gum-resin from Balscujiodendron Myrrha {Burseracece). 

Eastern Africa and southwestern Arabia. 

Irregular pieces, brownish yellow or reddish-brown, wax-like fracture, 
translucent with a wine-red color when in thin splinters or pieces; yields a light 
brownish-yellow powder; odor balsamic, peculiar; taste bitter, acrid. Triturated 
with water it forms a brownish-yellow emulsion. 

Contains volatile oil, resin and gum. 

It is tonic, stimulant, blennorrhetic. 

Slightly astringent. 

Dose. — Powder, S to 30 grains; Tincture, 15 to 60 minims. 

It is contained in Compound Iron Mixture, Pills of Aloes and Myrrh. 
Com. Iron Pills, Com. Pills of Galbanum, Tinct. of Aloes and Myrrh. 

1258. Resina. Resix, Colophony. 

The resin left after distilling off the volatile oil from turpen- 
tine (1267). 

The United States. Large quantities are produced in North 
Carolina. 

Transparent, amber-colored, hard, brittle, with a glossy fracture, odor 
feeble terebinthinate, taste resinous. Melts at about I35 C C. (275 C F.) Soluble 
in alcohol, ether, volatile oils, and fixed oils; insoluble in water. 

Consists of abietic anhydride. 

Used as an ingredient in plasters, cerates, and ointments. 

1259. Guaiaci Resina. Guaiac Resix. 

The resin of the heart wood of Guaiacum officinale (Zygop/iy/- 
lacecE) . 

West Indies and South America. 

Dark, greenish-brown, in large masses, nearly black, in thin splinters, 
translucent, brittle, fracture glassy; fusible, emitting an aromatic odor when 
melted; somewhat acrid to the taste. The powder is light-grayish, but 
becomes green on exposure to the air. 

Properties. — Diaphoretic, diuretic, alterative, stimulant. 

Dose. — Powder, S to 15 grains; Tincture and Ammoniated Tincture, 30 to 
60 minims. 



.382 ABOUT DRUGS. 

1260. Mastiche. Mastic. 

The hardened resinous exudation from Pistacia Lentiscus 
{Terebinthacece). 

Mediterranean countries. 

Globular tears, smaller than a pea, pale yellow, transparent, brittle, 
yielding a white powder; odor and taste resinous. Soluble in absolute 
■alcohol. 

Used in pills of aloes and Mastic. 

1261. Pix Burgundica. Burgundy Pitch. 

Prepared resinous exudation from Abies excelsa (Coniferce). 

Southern Europe. 

Hard at ordinary temperature, but very soft, running, when warmer, 
•opaque or translucent. Brittle when cold, fracture glossy; yellowish brown, 
somewhat aromatic. 

Used as an ingredient in Burgundy pitch plaster and in pitch plaster with 
•cantharides. 

1262. Scammonium. Scammony. 

A hardened, resinous exudation, from the root of Convolvulus 
Scammonia (Convolvulacecz) . 

Minor Asia. Smyrna. 

Irregular pieces, or circular cakes, greenish-gray, porous, fracture angu- 
lar ; odor peculiar, somewhat cheese-like; taste slightly acrid. 

Consists mainly of the resin called scam?nonin. Cathartic. 

Dose. — Powder, 5 to 15 grains ; the official Resin of Scammony is purified 
Scammony; dose, 3 to 10 grains. 

1263. Benzoinum. Benzoin. 

balsamic resin from Styrax Benzoin (Styracece). 

Siam, Sumatra. 

Resinous masses of a grayish-brown color, the exterior being darker 
when longer exposed, interiorly mottled, large tears or " almonds" of pure, 
•opaque resin being imbedded in a mass of translucent, yellowish-brown 
resin, the tears being milk-white in the fracture; odor agreeable, balsamic; 
taste faintly but gratefully aromatic. Benzoin is almost entirely solution in 
solution of potassa, and also in 5 parts of warm alcohol. It emits vapors of 
benzoic acid when heated. 

Contains from 15 to 20 per cent, of benzoic acid and a minute quantity of 
volatile oil. 



ABOUT DRUGS. 383 

Used in external applications as a cosmetic, as a preservative of fats, and 
as an aromatizer. 

Preparations. — Benzoinated Lard, Tincture of Benzoin and Compound 
Tincture of Benzoin. 

1264. Balsamum Peruvianum. Balsam of Peru. 

A thick liquid balsam obtained from Myroxylon Pereiroz 
{Leguminosoz). 

Central America. 

Brownish-black, lighter or reddish-brown and transparent in thin layers. 
Odor agreeable, balsamic, reminding of a combination of vanilla and benzoin. 
Taste warm, bitterish, finally acrid. Wholly soluble in 5 parts of alcohol. 

Contains about 6 per cent, cinnamic acid. About 30 per cent, consists of 
xesins; and 60 per cent, of benzyl cinnamate (cinnamein), which is an oily 
liquid. 

Uses. — Externally it is used as a cure for the itch, and it is added to 
ointments as a preservative. Internally it is expectorant and blennorrhetic. 

1265. Balsamum Tolutanum. Balsam of Tolu. 

A semi-solid or solid balsamic resin obtained from Myroxylon 
toluifera (Legu?ninosce) . 

Venezuela and New Granada. 

Yellowish-brown, or brownish-yellow, transparent in thin layers, brittle 
when cold; soft at ordinary room temperatures, running when warmed; odor 
agreeable, balsamic; taste feeble but pleasantly aromatic. Entirely soluble 
in alcohol. 

Contains cinnamic acid, volatile oil and minute amounts of other aromatic 
bodies. 

Used as a blennorrhetic, but mainly as a pleasant addition to cough mix- 
tures, etc. 

Preparations. — Tincture and Syrup. 

1266. Styrax. Storax. 

A balsam prepared from the inner bark of Liquidambar 
orientalis (Hamamelacece). 

Asia Minor. 

Tenacious, semi fluid, sticky, gray, opaque, transparent in thin layers. 
Odor agreeable, balsamic; taste balsamic. Entirely soluble in an equal 
weight of warm alcohol. 

Contains styrol, cinnamic acid, styracin, and other cinnamic ethers, 
resin, etc. 

Used in Compound Tincture of Benzoin. 



3^4 ABOUT DRUGS. 

1267 Terebinthina. Turpentine. 

The concreted oleoresin-from Pinus australis and other species 
: P h Co Kifcrez). 

N : rth Carolina and other southeastern portions of the United 

S:a:es. 

I e iowish, tough masses, brittle in the cold, granular interiorly; odor and 
:as:e :t:t'::r.\:.:r. a:e 

Consists of volatile oil and resin. 

Used as a sumaian: :r.cre tr :n some ointments and plasters. 

1268. Terebinthina Canadensis. Canada Turpentine* 
[Balsam c f Fir.] 

A thick liquid oleoresin from Abies balsamea (Coniferea:). 
Pa.e yellowish, :r faintly greenish, transparent; odor terebinthinate; 

:as:e z;::er: = h. 5ligh:iv acrii. En::re".y sciu'zie in ether. :hi:r::rrm :enz:i. 

1269. Pix Liquida. Tar. 

destructive iistillatic r c: the v-rcc ci ::' P:*:u: f.:.'u:?>-:s and :• t'other 
species of Pinus (Conifer a). 

North Carolina. Produced also in many other localities in 
Europe and America. 

Thick, viscid, blackish-brown, transparent in thin layers, granular and 
opaque when old; heavier than water; reaction acid; odor empyreumatic 
terebi d : b i : a I e taste sharp, and smoky . Soluble in alcohol. 

Contains oil of turpentine, acetic acid, creasote, phenol, pyrocatechin, 
resin, etc. The granular appearance of old tar is due to crystals of pyro- 
ca:e:hin. ~h::h 5 sziur'.e in water as well as alcohol, and pungent. 

Uses — 5 : i m a '. a n : . ': '. e n norrhetic. Also used externally in skin affections. 

Preparations. — Syrup ana C;n:men:. 

1270. Copaiba. " Balsam of Copaiba." 

T;;e oleoresin "n :: a " balsam ".] ::' C:r. ::/■:>-.: Z.: •;_-.-.:'. •;-"; and 
other species of Copaifera (Lcguminosa). 

£j'.'c.Z A. 

A pale yellowish or brownish-yellow transparent or translucent, syrupy 
liquid: odor peculiar, aromatic, nauseous: taste nauseous, persistently bitter, 

a:: a Reaiiiy s:iu:ie in a its: hate ai:ch:i 
Contains : : latile oil and resin. 
Properties. — Expectorant, blennorrhetic, diuretic diaphoretic. 

Dose. — : : :•: minims 



ABOUT DRUGS. 385 

CHAPTER LXXI. 

FATS AND FIXED OILS. 

1271. Adeps. Lard. 

Hog's lard, recently rendered and refined. 

A soft, white, free from rancidity, of bland taste. Melts at 35° C. (95' F.) 

Used in preparing ointments and cerates. 

1272. Cera. Wax. 

A peculiar solid fat deposited by the bee. 

Cera Flava is the natural, or yellow, wax. 

Cera Alba is white wax prepared by bleaching the yellow wax. 

Wax melts at about 64° C. (147 F.); is soluble in ether and chloroform. 

Used in cerates, ointments and plasters. 

1273. Cetaceum. Spermaceti. 

A peculiar fat from Physeter marrocephalus, the sperm whale. 
Perfectly white, somewhat translucent in thin layers, unctuous, scaly, 
crystalline, inodorous, of a bland taste. Melts near 50' C. (122° P.), and con- 
geals at about 45 C. (113° F.) 

Used in cerates and ointments. 

1274. Sevum. Suet. 
Recently rendered mutton-suet, free from rancidity. 
White, nearly inodorous, bland. Melts between 45^ and 50° C. (113 and 
122° F.). 

Used in mercurial ointment. 

1275. Oleum Adipis. Lard Oil. 

The fixed oil expressed from lard at a low temperature. 
Colorless or pale yellowish, nearly inodorous, bland, free from rancidity. 

1276. Oleum Amygdalae Expressum. Expressed oil of 
Almoxd. Sweet oil of Almond. 

The fixed oil expressed from the Bitter and Sweet Almond. 
Nearly colorless, or of a pale straw color, ct a mild nutty odor and taste. 
Used in " cold cream" and phosphorated oil. 

1277. Oleum Gossypii Seminis. Cotton Seed Oil. 
From the seed of Gossypium herbaceum (Malvaceae), and other 

species of Gossypium . 

Pale yellow, inodorous, bland. 

1278. Oleum Lini, Flaxseed Oil. Linseed Oil. 
Expressed from flaxseed without the aid of heat (1231). 



386 ABOUT DRUGS. 

A yellowish or light yellowish-brown drying oil of a mild peculiar odor 
and bland taste. 

1279. Oleum Morrhuae. Cod Liver Oil. 

From the fresh livers of Gadus Morrhua and other species 
of Gadus (Pisces). 

Northeastern coasts of the United States, Newfoundland, 
Norway. 

Colorless or pale yellow, thin, of fishy odor and a bland, slightly fishy 
taste. 

1280. Oleum Olivae. Olive Oil. Sweet Oil. 
From the ripe fruit of the Olive, Oka euroficza (Oleacece). 
France, Italy, Spain. 

Pale yellow; of a faint agreeable nutty odor and taste, bland. 

1281. Oleum Ricini. Castor Oil. 

From the seed of Ricinus communis (Euphorbiacece). 

The United States. Italy. 

Colorless, or nearly so, with a pale yellowish tint, viscid, odor feeble but 
nauseating; taste bland but nauseating, finally slightly acrid. Soluble in an 
equal weight of alcohol and miscible with absolute alcohol in all proportions 

1282. Oleum Sesami. Sesamum Oil. Benne Oil. 
From the seed of Sesamum indicum (Pedaliacece). 

Light yellow, inodorous or nearly so, bland. 

1283. Oleum Theobromae. Oil of Theobroma. Butter 
of Cacao. 

A solid fat from the seed of Theobratna Cacao {Sterculiacea) . 

Mexico. 

Yellowish-white; odor faint but rather agreeable; taste bland, reminding 
somewhat of chocolate. Melts at 30° to 35 C. (86° to 95 s F.). 
Used for making suppositories. 

1284. Oleum Tiglii. Croton Oil. 

From the seed of Croton Tigliutn {Euphorbiacecz). 

India. 

Yellow or brownish-yellow, slightly fluorescent; odor feeble, fatty; taste 
first mild, oily, then acrid, burning. Applied to the skin it vesicates. Incom- 
pletely soluble in alcohol, quite soluble in ether and chloroform. 

Used sometimes internally as a drastic cathartic. Externally as an irri- 
tant and suppurant. 

Dose one-fourth to two drops, in olive oil, or otherwise well diluted or 
distributed. 






ABOUT DRUGS. 387 

CHAPTER LXXII. 

VOLATILE OILS AND CAMPHORS. 

1285. Oleum Amygdalae Amarae. Oil of Bitter Al- 
mond. 

A volatile oil produced in bitter almond by maceration with water and 
obtained by subsequent distillation. 

Colorless or pale yellow; odor peculiar, hydrocyanic acid-like; taste bit- 
ter, burning. Scarcely soluble in alcohol. 

1286. Oleum Anisi. Oil of Anise. 
From Anise (1212). 

Colorless or pale yellow, having the peculiar odor of anise, and a sweetish, 
aromatic, burning taste. Soluble in an equal weight of alcohol. Solidifies 
at from io° to 15 C. (50 to 59° F.). 

Used as a stimulant carminative, and as a flavoring agent. 

Oil of Star Anise resembles the true Oil of Anise but does not congeal 
until at about 2° C. (35. °6 F.). 

1287. Oleum Aurantii Corticis. Oil of Orange Peel. 
Expressed from the peel of fresh sweet orange. 

Pale yellowish, of the characteristic odor of sweet orange; an aromatic, 
burning; somewhat bitter taste. 
Used for flavoring. 

1288. Oleum Aurantii Florum. Oil of Orange Flowers. 
Oil of Neroli, 

Yellowish or brownish-yellow, of the fragrant odor of orange flowers; 
taste aromatic, bitterish, burning. 
Used in perfumery. 

1289. Oleum Bergamii. Oil of Bergamot. 
Expressed from the rind of the fruit of Citrus Berga?nia 

{Aurantiacece). 

Pale greenish; odor very fragrant. 
Used in perfumery. 

1290. Oleum Cari. Oil of Caraway. 
Distilled from Caraway (1215). 

Colorles-s or pale yellowish, of the peculiar odor of caraway, and a charac- 
teristic spicy taste. 

Used as a stimulant carminative and for flavoring. 



388 ABOUT DRUGS. 

1291. Oleum Caryophylli. Oil of Cloves. 
Distilled from Cloves (1.191) 

Light brown, or brownish-yellow, of a strong spicy odor of cloves, and 
burning taste. Very soluble in alcohol. 

1292. Oleum Cinnamomi. Oil of Cinnamon. 

Pale yellowish-brown, of the strong characteristic aromatic odor of cin- 
namon, and a spicy, burning taste (1170). 
Used for flavoring. 

1293. Oleum Copaibae. Oil of Copaiba. 
The volatile oil distilled from Copaiba. 

Pale yellowish, or nearly colorless, of the odor of copaiba, and a pungent, 
bitterish taste. 

Used for the same purposes as copaiba (1270). 
Dose. — 5 to 15 minims.' 

1294. Oleum Coriandri. Oil of Coriander. 
Distilled from Coriander (1219). 

Colorless or pale yellowish, aromatic, spicy. 
Used for flavoring. 

1295. Oleum Cubebae. Oil of Cubeb. 
Distilled from Cubeb (1220). 

Pale greenish, or greenish-yellow, of the odor of cubeb, and a hot, cam- 
phoraceous taste. 

Used for the same purposes as Cubeb (1220). 
Dose.— 5 to 15 minims. 

1296. Oleum Eucalypti. Oil of Eucalyptus. 
Distilled from fresh Eucalyptus leaves (1202). 

Colorless or pale yellowish, of the strong, peculiar, camphoraceous odor 
of Eucalyptus, and a pungent, cooling taste. 
Used as an antiseptic. 

1297. Oleum Fceniculi. Oil or Fennel. 
Distilled from Fennel (1221). 

Colorless or pale yellow, sweetish, aromatic, spicy. 
Used as a carminative and flavoring agent. 

1298. Oleum Gaultheriae. Oil of Wintergreen. 
Distilled from Gaultheria. 

Colorless or pale yellow, or reddish-yellow, of a peculiar strong odor, and 
a sweetish, warm, aromatic taste. Consists mainly of methyl salicylate. 
Used as an antiseptic and for flavoring. 



ABOUT DRUGS. 389 

1299. Oleum Juniperi. Oil of Juniper. 
Distilled from Juniper berries (1223). 

Colorless, or pale yellowish, of the characteristic odor of Juniper, and a 
warm, aromatic, sweetish, terebinthinate taste. 
A constituent of gin. 

1300. Oleum Lavandulae. Oil of Lavender. 
Distilled from the flowering tops or herb of Lavender (1193). 
[Called in the trade "Oil of Garden Lavender."] 

Colorless or pale yellowish, of strong but coarse Javender odor, and a 
pungent, bitterish taste. 
Used in liniments. 

1301. Oleum Lavandulae Florum. Oil of Lavender 
Flowers. 

Distilled from fresh Lavender flowers (1193). 
Colorless or pale yellowish, of a superior fragrant lavender odor, and a 
pungent, bitterish taste. 

Used for flavoring and in perfumery. 

1302. Oleum Limonis. Oil of Lemon. 
Expressed from fresh lemon peel. 

Pale yellow, of the aromatic fragrance of lemon, and an agreeable, 
aromatic, pungent taste. 
Used for flavoring. 

1303. Oleum Menthae Piperitae. Oil of Peppermint. 
Distilled from Peppermint (1187). 

Colorless or pale yellowish, having a strong odor of peppermint, and a 
burning, aromatic taste, producing in the mouth a cooling sensation, when air 
is inhaled. 

Its most important constituent is menthol. 

Used as a carminative, and for flavoring. 

1304. Oleum Pimentae. Oil of Allspice. 
Distilled from Pimenta. 

Pale brownish-yellow, of the strong spicy odor, and taste of allspice. 
Used for flavoring. 

1305. Oleum Rosae. Oil of Rose. 

Distilled from the fresh flowers of Rosa damascena {Rosacea). 
France and other Mediterranean countries. 

Very pale yellowish, of a powerful rose odor, and a sweetish aromatic 
taste. Solidifies at about io° C. (50 F ) 
Used for flavoring, and in perfumery. 



39° ABOUT DRUGS. 

1306. Oleum Rosmarini. Oil of Rosemary. 
Distilled from Rosemary leaves (1206). 

Colorless or pale yellowish, agreeably aromatic, pungent, camphoraceous. 
Used in liniments, and for flavoring, and is an important constituent of 
Cologne water. 

1307. Oleum Sabinae. Oil of Savin. 
Distilled from Juniperus Sabina (Conifer a). 

Colorless, or pale yellowish, of the peculiar strong, somewhat terebinthi- 
nate, odor of Savin, and a burning, bitterish, camphoraceous taste. 
Stimulant, irritant. 
Dose. — About 5 drops. 

1308. Oleum Sassafras. Oil of Sassafras. 
Distilled from Sassafras (11 79). 

Colorless, or pale yellowish, of the characteristic odor of Sassafras, and a 
warm aromatic taste. 

Used as a carminative and for flavoring. 

1309. Oleum Sinapis Volatile. Volatile Oil of Mus- 
tard. 

A volatile oil produced by the maceration of black mustard 
with water, and obtained by subsequent distillation (1235). 
Colorless, or pale yellowish, extremely offensive, pungent, acrid. 
Used as a rubefacient in liniments. 

1310. Oleum Terebinthinae. Oil of Turpentine. 
The volatile oil distilled from Turpentine (1267). 
Colorless, thin, of a characteristic odor, and burning taste. 

Used in liniments. It is also stimulant, diuretic, anthelmintic and pur- 
gative. 

Dose. — As a stimulant, 5 to 15 minims. 

131 1. Camphora. Camphor. 

A stearopten (C 10 H 16 O) derived from Cinnamomum Ca?nphora 
(Lauracece). 

China, Japan, Formosa. 

White, translucent, in thin fragments perfectly transparent, tough, crys- 
talline, readily pulverizable when moistened with alcohol, ether or chloroform. 
Odor characteristic, penetrating; taste pungent. Melts at 175 C. (347° F.), 
.boils at 205 C. (401° F.), and sublimes without residue. Is readily ignited, 



ABOUT DRUGS. 391 

and burns with a smoky flame. Entirely and readily soluble in alcohol, 
ether, chloroform, volatile oils, fixed oils. 

Properties. — Stimulant of brain and circulation. Prophylactic and anti- 
septic. Diaphoretic. 

Dose. — 1 to 5 grains. 

Preparations. — Camphor Water, Spirit of Camphor, Cerate and Lini- 
ment. 

1312. Menthol. Menthol. 

The stearopten from oil of peppermint. 

In small white or transparent slender, prismatic crystals having the com- 
position CioH 20 0. Odor of peppermint; taste pungent, afterwards cooling. 
Readily soluble in alcohol and ether. 

Properties. — Stimulant, antiseptic, anti-neuralgic. 



CHAPTER LXXIII. 

ANIMAL DRUGS. 



(NOT ELSEWHERE MENTIONED.) 

1 3 1 3- Cantharis. Cantharides. 

Spanish Flies. 

The entire insect Cantharis vesicatoria {Coleoptera), 

Spain, Southern Russia, and other localities in southern 
Europe. 

About an inch long, %. inch broad; hard shell, shining copper green; odor 
'peculiar, nauseous; taste nauseous, burning. The powder is grayish-brown, 
with green, shining particles. Applied to the skin, it vesicates. 

Contains the vesicant principle, cantharidin. 

Uses. — Stimulant, diuretic ; externally rubefacient, vesicant 

Dose of the Tincture, 5 to 15 minims. 

The preparations for external use are two Cerates, Collodion, Liniment, 
and Pitch Plaster with Cantharides. 

1314. Fel Bovis. Ox-Gall. 

The fresh gall of beef cattle. Bos Taurus {Mammalia). 
Brownish green or dark green, of a oeculiar nauseous odor and an 
intensely bitter taste. 



392 ABOUT DRUGS. 

In a purified state, evaporated down to an extract-like soft solid, it is 
still sometimes used as a purgative. 
Dose, 5 to 3 grains. 

1315. Moschus. Musk. 

The dried secretion from the preputial follicles of Moschus 
Moschiferus (Mammalia) . 

Dark reddish-brown masses, or a crummy granular coarse powder, of a 
peculiar and very strong, penetrating, persistent odor, and bitterish taste. 
Contains resinous matter, etc 

Uses. — Stimulant, antispasmodic. Also used in perfumery. 
Dose of musk, 5 to 10 grains ; Tincture, 15 to So minims. 

1316. Pepsinum. Pepsin. 

Pepsin is the digestive principle of the gastric juice, obtained 
from the mucous membrane of the stomach of the hog. 

The Saccharated Pepsin of the Pharmacopoeia is pepsin 
mixed with powdered milk sugar. It is white, and of slight, 
but not disagreeable odor and taste. 

Pepsin digests albumin, and the Pharmacopoeia requires that 1 part of 
Saccharated Pepsin shall digest at least 50 times its weight of hard 
white of egg within six hours, at 39 3 C. (i02°F.), when mixed with 500 parts 
of water acidulated with 7.5 parts of hydrochloric acid. 

Used in dyspepsia and apepsia. 



CHAPTER LXXIV. 

THERAPEUTIC CLASSIFICATION OF MEDICINES. 

1317. Medicines are classified according to their therapeutic 
effects and mode of use. 

Thus they may first be divided into two great groups: 1, Sys- 
temic Medicines, which act on the whole body through their 
effect upon its organs and their functions; and 2, Topical 
Medicines, having local or limited effects. 

1318. The systemic medicines may be divided into three 
classes: 1, Those acting upon the digestion, nutrition and the 



ABOUT DRUGS. 393 

temperature of the body; 2, Those acting upon the several 
organs, as upon the nervous system, the circulatory organs, 
sexual organs and the alimentary canal; and 3, Those affecting 
the secretions. 

1319. Systemic Medicines of the first class are: digestants, 
tonics, alteratives and antipyretics. 

Those of the second class are: A, hypnotics, mydriatics, ano- 
dynes, anaesthetics, antispasmodics, motor-excitants and motor- 
depressants; B, stimulants and sedatives influencing the circula- 
tion; C, aphrodisiacs, anaphrodisiacs, oxytocics, uterine seda- 
tives, and emmenagogues; D, emetics, gastric sedatives, carmina- 
tives, cathartics and anthelmintics. 

Systemic Medicines of the third class are: Diuretics, dia- 
phoretics, expectorants, astringents and antacids. 

1320. Topical Medicines are divided into: antiseptics, irri- 
tants, demulcents, emollients and protectives. 

1321. Digestants are medicines which aid digestion. 
Ex. Pepsin, pancreatin, papain, malt extract. 

1322. Tonics are remedies which restore strength and 
energy to the body or its parts, or increase its vigor. The 
tonics are divided into vegetable tonics, or bitters, and mineral 
tonics. 

Bitter Tonics are numerous. Among them are gentian 
quassia, calumba, serpentaria, anthemis, bitter orange peel, absinthium, 
cinchona, salix, Hydrastis, etc. 

Mineral Tonics include the preparations of iron and phos- 
phorus, and the mineral acids. 

1323. Alteratives do not act upon particular organs, but 
establish conditions favorable to the re-establishment of the 
healthy functions of the system. 

Among the most commonly employed alteratives are the 
preparations of mercury and gold, iodi?ie and iodides; arsenic j 
phosphates and hypophosphites; cod-liver oil; sarsaparilla, guaiac, 
stillingia and colchicum. 



394 ABOUT DRUGS. 

1324. Antipyretics reduce the temperature of the body 
when abnormally high, as in fevers. 

Ex. — Antipyrin, acetanilid, quinine, salicin, salicylates, salol, acet- 
phenetidin, resorcin, hydroquinone, chinoline, thalline and kairine. 

1325. Hypnotics are remedies inducing sleep. They may 
be narcotics, which stupefy, or anodynes, which lessen excitement 
and relieve pain. 

The principal hypnotics are opium, morphine and codeine, hyoscy- 
amus, cannabis indica, bromides, chloral, paraldehyd, hypnone, ttrethan. 

1326. Mydriatic Anodynes are used to relieve pain (as 
analgesics and antispasmodics); they dilate the pupil, and in 
large dose produce restless delirium instead of sleep. 

Belladonna, hyoscyamus, stramonium, erythroxylon and antipyrin 
are mydriatic anodynes . 

1327. Anaesthetics are substances which, when f heir vapor 
is inhaled, produce insensibility to pain or to touch, and uncon- 
sciousness. 

The principal anaesthetics are ether, chloroform, nitroge?i mo?i- 
oxide, methylene bichloride and ethyl bromide. 

1328. Antispasmodics are medicines which relieve or pre- 
vent spasmodic pain or the spasmodic action of the muscles. 

Among them are camphor, valerian, asafetida, musk, cypripedium, 
ether. 

1329. Motor-Excitants are medicines which excite muscu- 
lar action by their stimulant effect upon the reflex centers of 
the spinal cord. 

The most important are nux vomica, strychnine and ignatia. 

1330. Motor-Depressants are medicines producing effects 
the opposite of those of the motor-excitants (1329). They 
depress the functions of the spinal cord and lessen muscular 
activity. 

Hydrocyanc acid, chloral, bromides, physostigma, gelsemium, con- 
turn, lobelia and tobacco are motor-depressants. 



ABOUT DRUGS. 395 

1331. Cardiac and Arterial Stimulants are medicines 
which increase the action of the heart and the force of the circu- 
lation of blood. 

Among the stimulants of the organs of circulation are: 
Alcohol, ether, ammonia, atropine, digitalis, strophanthus, strychnine y 
caffeine. 

1332 . Cardiac and Arterial Sedativesare medicines which 
diminish the force and frequency of the heart contractions, and 
depress circulation. They are the opposite of the cardiac 
and arterial stimulants (1331). 

Aconite, veratrum viride, gelsemium, veratrine, and antimony prep- 
arations are sedatives of this kind. 

*333- Aphrodisiacs are remedies which excite the func- 
tions of the genital organs when morbidly depressed. 

Anaphrodisiacs are the opposite of aphrodisiacs, depressing 
the sexual functions when excited. 

1334' Oxytocics are medicines which increase the contrac- 
tile power of the uterus. 

Ergot and cotton root bark are oxytocics. 

Uterine Sedatives are medicines which diminish or depress 
uterine contractions. 

Emmenagogues increase or re-establish the menstrual flow 
when suppressed from causes other than pregnancy or age. 

1335. Emetics are medicines which induce vomiting. 

The most important emetics are ipecac, apomo?-phine and mus- 
tard, copious draughts of warm water, tartar e?netic, zinc sulphate, 
copper sulphate, alum and subsulphate of 7nercury. 

1336- Carminatives are medicines which aid the expulsion 
of gases from the stomach and intestines. 

Drugs containing volatile oils, and the volatile oils them- 
selves, are used for this purpose, as anise, caraway, fennel, asafet- 
ida, oil of turpentine, eucalyptus, etc. 

1337. Cathartics are medicines which cause the evacua- 
tion of the bowels, either by increasing the peristaltic motion of 
the intestines, or by augmenting the intestinal secretions. 



39^ AEOUT DRUGS. 

Powerful cathartics are called drastic purgatives, and irritant 
cathartics producing watery stools by causing a copious increase 
of the secretions are called hydragogue cathartics, while medicines 
which relieve the bowels of their contents without irritation or 
purgation are called laxatives. 

Saline cathartics produce liquid stools not only by increasing 
peristalsis, but also by causing exosmosis of water from the 
blood vessels. 

Among the laxatives are castor oil, tamarinds, manna, frangula, 
rhamnus, purshiana and sulphur. 

Among the simple purgatives are rhubarb, aloes, senna, calomel 
and blue mass. 

The saline catliartics include the magnesium salts and rochelle 
salt. 

The drastic purgatives include jalap, scammony, gamboge, elaterin 
and elaterium, croton oil, podophyllum, etc. 

1338. Anthelmintics are medecines employed to kill or 
expel intestinal worms. Those that kill the worms are called 
vermicides; medicines which expel the worms are caled vermifuges. 
Among the anthelmintics are aspidium, brayera, chenopodium, 
granatum, kamala, pepo, santonica and santonin, spigelia, and oil of 
turpentine. ' 

I 339« Diuretics are medicines which increase the flow of 
urine. They may be grouped into alkaline, hydragogue and 
alterative diuretics. 

Acetate, nitrate and bicarbonate of potassium, lithium citrate and 
■chloride, and sodium acetate are alkaline diuretics. 

Squill, digitalis, caffeine, scoparius, and spirit of nitrous ether are 
hydrogogue diuretics. 

Buchu, pareira, uva ursi, chimaphila, juniqer, oil of turpentine, oil 
of santal, copaiba, cubeb, and matico are alterative diuretics. 

1340. Diaphoretics are medicines which increase or cause 
perspiration. They are grouped into nauseating, sedative, 
saline and special diaphoretics. When they are so powerful as 
to bring on profuse sweating they are called sudorifics. 



ABOUT DRUGS. 



397 



Nauseant diaphoretics are represented by ipecac and Dover's 
powder. Sedative diaphoretics by antimony preparations, aconite 
and veratrum vivide, salicylic acid and other antipyretics. Among 
the saline diaphoretics are solution of ammonium acetate, spirit of 
nitrous ether, potassium citrate. 

Pilocarpus is a powerful sudorific or special diaphoretic. 

1341. Expectorants are medicines employed to aid or 
modify the secretions of the air passages and promote the expul- 
sion of mucus and other fluids from the lungs and trachea. 

Among the sedative expectorants are ipecac (an emetic), tartar 
emetic (a sedative), pilocarpus (a diaphoretic) and lobelia (a motor- 
depressant). Grindelia is also a sedative expectorant. 

Among the stimulant expectorants (sometimes called blennor- 
rhetic) are senega, quillaia, squill, sanguinaria, ammoniac, benzoin, 
balsam of Peru, balsam of Tolu, eucalyptus, oil of turpentine, copaiba, 
tar, terebene, and ammonium chloride. 

1342. Astringents are medicines usea to diminish secre- 
tion, which they do by causing the contraction of the tissues 
with which they come in contact. 

Among the vegetable astringents are tannic and gallic acids and 
drugs containing tannins, such as nutgall, oak bark, catechu, kino, 
krameria, hamatoxylon, geranium, and rhus glabra. 

Inorganic astringents include the soluble salts of aluminum, silver, 
lead, zinc and copper, and certain iron salts. 

1343. Antacids are medicines which neutralize acids. 
The hydrates and carbonates of potassium, sodium, lithium and 

ammonium and the oxides, hydrates, and carbonates of calcium and 
magnesium are antacids. 

1344. Antiseptics are substances which prevent or arrest 
the decomposition of organic matter. They do this by prevent- 
ing or arresting the development of the germs by which such 
decomposition is caused. 

Disinfectants also arrest putrefaction and the formation of 
unwholesome or offensive products of decomposition; but while 
antiseptics simply prevent or arrest the development of the 
germs which cause the fermentation, putrefaction or other 



3q3 about drugs. 

organic changes, without destroying the products of decomposi- 
tion that may have been already formed, and without injury to 
healthy animal tissues, disinfectants always destroy the noxious 
products of decomposition, and frequently have an injurious 
or even destructive effect upon organic substances generally. 

Among the most commonly employed antiseptics are alcohol, 
boric acid, salicylic acid, carbolic acid, benzoic acid, thymol, volatile 
oils, as oil of eucalyptus and oil of cloves, quinine, populin, corrosive sub- 
limate, etc. 

Among the most powerful disinfectants are chlorine, bromine, 
iodine, potassium permanganate, sulphurous acid and the sulphites. 

1345. Irritants are medicines applied locally to produce 
counter-irritation, inflammation, vesication, suppuration, and 
destruction of tissue. 

Rubefacients are irritants producing powerful but tempor- 
ary congestion of the surface to which they are applied. All vola- 
tile oils are counter-irritants and rubefacients, but among the 
most common rubefacients are mustard, capsicum, and ammonia 
liniment. 

Vesicants are remedies which raise blisters when applied to 
the skin, such as cantharis, crotonoil, etc. 

Escharotics destroy the tissues with which they come in con- 
tact, and therefore cause sloughing and eschar. Among the 
esoharotics are the caustic alkalies, strong acids, bromine, zinc chlo- 
ride, solution of nitrate of mercury, etc. 

1346. Demulcents are remedies administered internally for 
their soothing effect upon irritated or inflamed surfaces. 

Among them are water, gums, and mucilages, decoctions of 
starch, barley, rice, althaia, etc. 

1347 Emollients are bland fatty substances, fomentations or 
poultices, glycerin, etc., applied externally to soften the skin. 



ABOUT DRUGS. 



399 



CHAPTER LXXV. 

1348. Dose Table of medicines in frequent use, includ- 
ing new remedies, in metric as well as apothecaries' 
weights and measures. 



Remedies. 



Absinthium , extr 

fluid extr 

Abstracts, see each drug. 

Acetanilid ' 

Acetphenetidin ... 

Achillea, fl. ext 

extr 

Acid, acet. dil 

arsenos 

liquor 

benzoic 

boric 

carbolic 

gallic 

" in albuminuria. 

hydriod., sir 

hydrobrom. dil. ... . 

hydrochlor. dil 

hydrocyan. dil 

lactic 

nitric, dil 

nitrohydrochlor 

dil... 

phosph. dil , 

salicyl 

sulph. arom 

«' dil 

tannic , 

Aconiti fol 

" extr 

" fl. extr 



Single Adult Dose. 



Metric Weights and Measure^ 

100 to 600 mGm 
1 to 2 C. c. 



300 
300 

200 
500 



300 



250 to 500 mGm 


4 to 


200 to 500 mGm 


3 to 


1 to 4 C. c. 


15 to 


2C0 to 600 mGm 


3 to 


4 to 6 C. c. 


1 to 


1 to 5 mGm 


i\ to 


0.10 toO on C. c. 


2 to 


mGm to 1 Gm 


5 to' 


mGm to 1 Gm 


5 to 


60 to 200 mGm 


1 to 


mGm to 1 Gm 


3 to 


mGm to 4 Gm 


8 to 


1 to 5 C c. 


15 to 


1 to 3 C. c. 


15 to 


0.50 to 2 C. c. 


8 to 


0.10 to 0.30 C. c. 


2 to 


1 to 4 Gm 


15 to 


0.50 to 2 C. c. 


8 to 


200 to 600 mGm 


3 to 


0.30 to 1.30 C. c. 


5 to 


0.50 to 4 C. c. 


8 to 


mGm to 1 Gm 


5 to 


0.20 to 1 C. c. 


3 to 


0.30 to 2 C. c 


5 to 


100 to 600 mGm 


1 to 


50 to 250 mGm 


1 to 


15 to 30 mGm 


ito 


0.05 to 0.20 C. c. 


1 to 



Oid Apothecaries' 
\ Weights and Measures. 

2 to 10 gr . 
15 to 30 min. 



8 gr. 
8 gr. 
60 min. 
10 gr. 
\\ fl. dr. 
tV gr. 
« min. 
15 gr. 
15 gr. 
3 gr. 
15 gr. 
60 gr. 
80 min. 
50 min. 
30 min. 
5 min. 
60 gr. 
31) min. 
10 gr. 
20 min. 
60 min. 
15 gr. 
15 min 
30 min. 
10 gr. 
4gr. 
igr. 
3 min. 



Note. — The dose for a child is found by dividing the age in years at next 
birthday by 24 and multiplying the adult dose by the quotient. 

The dose to # be administered hypodermatically \s one-half of the dose given 
by mouth. 

The dose to be administered by rectum is 25 per cent, larger than that 
administered by mouth. 



400 



ABOUT DRUGS. 



Remedies. 



Aconiti fol. tinct 

rad 

" abstr 

" extr 

" fl. extr 

" tinct 

" " Fleming. . 
Aconitina (pure, cryst.) 

Adonidin 

Aether 

spir 

•' comp. 

Agaricin 

Allii syr 

Aloe, purgtive 

decoct, comp 

extr. 

pil 

tinct 

et asaf. pil , 

" ferri pil . , 

" mast, pil , 

" myrrh, pil 

" " tinct. . . . 

Aloin 

Alstonia, fl. extr , 

Alumen 

ustum 

Ammoniacum 

mist 

Ammoniae spir. 

" arom 
Ammonii benzoas 

bromid 

carb 

chlorid 

iodid 

phosph 

picras , 

sulph , 

valer 

Amyl nitris 

Amylen. hydrat 

Amylum iodat 

Angustura, fl. extr 

Anthemis, extr. ...... , 

fl. extr , 

Antifebrin 



Single Adult Dose. 



Metric Weights and Measures. 


Old Apothecaries' 1 




Weights and Measures. 


0.50 to 1 C. c. 


8 to 15 min. 


30 to 100 mGm 


. 1 to 1^ gr. 


15 to 50 mGm 


i to 1 gr. 


5 to i5 mGm 


TS to i S r - 


0.05 to 0.15 C. c. 


1 to 2 min. 


0.10 to 0.25 C. c. 


2 to 4 min. 


0.05 to 0.20 C. c. 


1 to 3 min. 


0.15 to 0.30 mGm 


■gfo-to-zfa; S r - 


8 to 30 mGm 


i to i gr. 


2 to 4 C.'c. 


% to 1 fl. dr. 


2 to 5 C. c. 


30 to 80 min. 


2 to 4 C. c. 


| to i fl. dr. 



10 to 100 mGm 
5 to 15 C. c. 
200 mGm to 1 Gm 

15 to 60 C. c. 

30 to 200 mGm 
3 to 6 pills 

1 to 5 C. c. 

2 to 5 pills 

2 to 4 pills 
1 to 2 pills 

3 to G pills 

5 to 10 C c. 
8 to 60 mGm 
5 to 15 C. c. 
300 mGm to 1 Gm 

100 to 500 mGm 
0.500 to 2 Gm 
15 to 30 C. c. 

1 to 2 C. c. 
3 to 10 C. c. 

0.300 to 1.300 Gm 
0.300 to 2 Gm 

200 to 500 mGm 

0.300 to 2.200 Gm 

50 to 500 mGm 

0.500 to 1.500 Gm 

15 to 30 mGm 

200 mGm to 1 Gm 

100 to 500 mGm 

2 to 5 drops 
1 to 4 Gm 

0.20 to 2 Gm 

1 to 2.50 C. c. 
100 to 650 mGm 

2 to 4 C. c. 
250 to 500 mGm 



i to 1-*- gr. 

1 to 4 fl. dr. 
3 to 15 gr. 

| to 2 fl. ozs. 
& to 3 gr. 
3 to 6 pills 
15 to 80 min. 

2 to 5 pills 

2 to 4 pills 
1 to 2 pills 

3 to 6 pills 
1 to 2 fl dr. 
i to 1 gr. 

1 to 4 fl. dr. 
5 to 15 gr. 

2 to 8 gr. 
8 to 30 gr. 

| to 1 fl oz. 
15 to 30 min. 
i to 21 fl. dr. 
5 to 20 gr. 
5 to 30 gr. 

3 to 8 gr. 
5 to 40 gr. 

1 to 8 gr. 
8 to 24 gr. 
i to i gr. 
3 to 15 gr. 

' 2 to 8 gr. 

2 to 5 drops 
15 to 60 gr. 

3 to 30 gr. 
15 to 40 min. 

2 to 10 gr. 
30 to 60 min. 

4 to 8 gr. 



ABOUT DRUGS. 



401 



Single Adult Dose. 



Remedies. 



Metric Weights and Measures. 



. . . \ antipyretic. . . 
Antipynn j ana £ ?sic 

Ant. et pot. tart ,diaphor. . . 
emetic . . . 

Antim. oxid 

Antim. oxysulph 

pil. comp 

sulphid 

sulphurat 

{ expect 

vinum < r . 

I emet 

Apiol 

Apocyn, fl. extr 

Apomorphine 

Aqua amygd. amar. . . .... 

camph 

chlori 

creasoti 

laurocerasi 

Areca, fl. extr 

Argenti iodid 

nitras 

oxid 

Arnicae flor. . fl. extr 

" tinct 

rad., extr 

" fl. extr 

" tinct 

Arsenic — 

arsenous acid 

iodid 

sod. arsenate 

liqu. acid, arsen 

" arsen. et hydr. iod 

" pot. arsenitis. . . 

" sol. arsenatis. . . . 

Asafoetida 

mist 

Pil 

tinct 

Asarum, fl. extr 

Asclepias, fl. extr 

Aspidium 

fl. extr 

oleoresin 

Aspidosperma. 

abstr 

extr 



500 mGm 

4 

30 

50 

30 

1 

30 

30 

0.06 

2 

200 

0.20 

2 

5 

10 

5 

5 

0.50 

5 

60 

15 

30 

0.25 

1 

60 

0.30 

2 

1 

1 

1 

0.10 

10 

0.10 

0.10 

300 mGm 

15 

2 

2 

1 

1 

4 

4 

1 

1 

0.500 

200 



o 2 Gm 
o 1 Gm 
o 10 mGm 
o 120 mGm 
o 250 mGm 
o 100 mGm 
o 3 pills 
o 100 mGm 
o 100 mGm 
o 0.50 C. c. 
o 5 C. c. 
o 300 mGm 
o2C. c. 
o 4 mGm 
o 15 C. c. 
o 60 C. c. 
o 15 C. c. 
o 15 C. c. 
o2 C. c. 
o 15 C. c. 
o 125 mGm 
o 30 mGm 
o 125 mGm 
o 1.50 C. c. 
o 3 C. c. 
o 200 mGm 
ol.50C. c. 
o 6 C. c. 

o 3 mGm 
o 3 mGm 
o 3 mGm 
oO.SO C. c. 
o 0.50 C. c. 

0.50 C. c. 

0.50 C. c. 

1 Gm 

30 C. c. 

6 pills 

4C. c. 
o2C. c. 
o2C. c. 
o 15 Gm 
o 15 C. c. 
o 4 Gm 
o 3 Gm 
o 1 Gm 
o 500 mGm 



Old Apothecaries'* 
Weights and Measures. 



13 



30 gr. 
15 gr. 

igr. 

2gr. 
4gr. 
2gr. 

3 pills. 
2gr. 
2gr. 

8 min. 
80 min, 

5 gr. 
30 min. 
tV gr. 

4 fl. dr. 
2 fl. ozs. 
4fl. dr. 
4 fl. dr. 
30 min. 
4 fl. dr. 
2gr. 
igr. 
2gr. 

20 min. 
45 min. 
3gr. 
20 min. 
90 min. 

■h gr. 
in g r - 
inr g r - 

8 min. 
8 min. 
8 min. 
8 min. 
15 gr. 
1 fl. oz. 

6 pills 
60 min. 
30 min. 
30 min. 
4 dr. 

4 fl. dr. 
60 gr. 
40 gr. 
15 gr. 
8gr. 



4-02 



ABOUT DRUGS. 



Remedies. 



Aspidosperma, fl. extr 

tinct 

Aspidospermine 

Atropine, and salts . . . 
Aurant, amar., fl. extr 

tinct 

Auri et Sodii chlorid. . 
Azedarach, fl. extr.. . . 
Bebeerine, and salts . 

Bellad. fol 

" abstr 

" extr 

" fl. extr 

" tinct 

rad 

" abstr 

*' extr 

" fl. extr 

" tinct 

Berberine, and salts. . 

Berberis, fl. extr 

Betol 

Bismuthi citras. 

et ammon. citr. . . 

oxid 

salicyl 

subcarb . , 

subnitr 

tannas 

valer 

Boldus, fl. extr 

Brayera 

fl. extr 

inf 

Bromum , 

Brucine, and salts 

Bryonia, fl. extr 

tinct 

Buchu, fl. extr. ...... 

Caffeine, and salts 

Calamus, fl. extr 

Calcii brom 

carb 

hypophosph 

iodid 

lactophosph. syr. . 

phosphas 

sulphid 

Calcis syrupus 



Single Adult Dose. 


Metric Weights and Measures. 


Old Apothecaries" 
Weights and Measures. 


1 to 3 C. c. 


15 to 45 min. 


5 to 15 C. c. 


1 to4fl. dr. 


60 to 300 mGm 


1 to 3 gr. 


0.50 to 2 mGm 


Tib- to h g r - 


1 to IOC. c. 


15 to 160 min. 


5 to 30 C. c. 


1 to 4 fl. dr. 


2 to 4 mGm 


A to tV g r - 


1 to 5 C. c. 


15 to 80 min. 


200 to 600 mGm 


3 to 10 gr. 


200 to 500 mGm 


3 to 8 gr. 


60 to 200 mGm 


1 to 3 gr. 


6 to 20 mGm 


T* to \ gr. 


0.15 to 0.30 C. c. 


1 to 4 min. 


0.40 to 1 C. c. 


8 to 15 min. 


60 to 200 mGm 


1 to 3 gr. 


30 to 100 mGm 


i to H Sr. 


5 to 10 mGm 


■h to £ gr. 


0.10 to 0.20 C. c. 


1 to 3 min. 


0.20 to 0.60 C. c. 


3 to 10 min. 


0.200 to 1 Gm 


3 to 15 gr. 


1 to 2 C. c. 


15 to 30 min. 


1 to 2 Gm 


15 to 30 gr. 


0.200 to 1 Gm 


3 to 15 gr. 


0.100 to 1 Gm 


1 to 15 gr. 


0.200 to 1 Gm 


3 to 15 gr. 


0.200 to 1 Gm 


3 to 15 gr. 


0.200 to 2 Gm 


3 to 30 gr. 


0.200 to 2 Gm 


3 to 3D gr. 


0.200 to 2 Gm 


3 to 30 gr. 


0.100 to 1 Gm 


1 to 15 gr. 


0.20 to 1 C. c. 


3 to 15 min. 


8 to 15 Gm 


2 to 4 dr. 


8 to 15 C. c. 


2 to 1 fl. dr. 


60 to 250 C. c. 


2 to 8 fl. ozs. 


30 to 100 mGm 


\ to \\ gr. 


1 to 4 mGm 


■fa to & gr. 


1 to 2 C. c. 


15 to 30 min. 


2 to 5 C. c. 


30 to 80 min. 


2 to 10 C. c. 


30 to 160 min. 


60 to 300 mGm 


1 to 4 gr. 


1 to 4 C. c. 


15 to 60 min. 


0.300 to 2 Gm 


5 to 30 gr. 


1 to 4 Gm 


15 to 60 gr. 


0.200 to 1 Gm 


3 to 15 gr. 


60 to 200 mGm 


1 to 3 gr. 


5 to IOC. c. 


1 to 2 fl. dr. 


1 to 2 Gm 


15 to 30 gr. 


15 to 60 mGm 


i to 1 gr. 


1 to 2 C. c. 


15 to 30 min. 



ABOUT DRUGS. 



4°3 



Remedies. 



Calend. fl. extr 

ct 

Calomel 

Calumba, extr 

fl. extr 

tinct 

Calx. Sulphurata 

Cambogia .. 

Camphora 

aqua 

spir 

monobrom 

Canella, fl. extr 

Cannabin, tannat 

Cannabis indica 

" abstr.. 
" extr... 
" fl. extr 
" tinct... 
Cantharis 

fl. extr 

tinct 

Capsicum 

fl. extr 

oleores 

tinct 

Cascarilla, fl. extr 

Castanea, fl. extr 

Castoreum 

tinct 

Catechu 

tinct 

Caulophyll, fl. extr 

Chimaphila. fl. extr 

Chinoidinum 

Chinolina, and salts 

Chirata, fl. extr.. 

tinct 

Chloral 

croton 

Chloralamid 

Chloroform 

mist 

spir 

Chrysarobin 

Cimicif., extr. 

fl extr. 

tinct 



Single Adult Dose. 



Metric Weights and Measures. 


Old Apothecaries'* 
Weights and Measurts. 


1 to 4 C. c. 


15 to 60 min. 


4 to 15 C. c. 


1 to 4 fl. dr. 


10 to 500 mGm 


i to 8 gr. 


200 to 600 mGm 


3 to 10 gr. 


1 to 4 C. c. 


15 to 60 min. 


5 to 15 C. c. 


1 to 4 fl. dr. 


15 to 60 mGm 


i to 1 gr. 


60 to 250 mGm 


1 to 4 gr. 


100 to 600 mGm 


H to 10 gr. 


15 to 60 C. c. 


\ to 2 fl. ozs. 


0.50 to 2 C. c. 


8 to 30 min. 


100 to 300 mGm 


2 to 5 gr. 


1 to 4 C. c. 


15 to 60 min. 


1 to 15 mGm 


fa to i gr. 


200 to 400 mGm 


3 to 6 gr. 


100 to 200 mGm 


H to 3 gr. 


10 to 60 mGm 


\ to 1 gr. 


0.20 to 0.40 C. c. 


3 to 6 min. 


1 to 2 C. c. 


15 to" 30 min. 


30 to 60 mGm 


i to 1 gr. 


0.03 to 0.06 C. c. 


\ to 1 min. 


0.50 to 1 C. c. 


8 to 15 min. 


60 to 200 mGm 


1 to 3 gr. 


0.06 to 0.20 C. c. 


1 to 3 min. 


10 to 30 mGm 


i to \ gr. 


0.50 to 1 C. c. 


8 to 15 min. 


3 to IOC. c. 


40 to 150 min. 


3 to lOC.c. 


40 to 150 min. 


0.400 to 1 Gm 


6 to 15 gr. 


1 to4C. c. 


15 to 60 min. 


1 to 2 Gm 


15 to 30 gr. 


2 to 8 C. c. 


\ to 2 fl. dr. 


1 to 2 C. c. 


15 to 30 min. 


2to4C. c. 


30to60C.c. 


0.200 to 2 Gm 


3 to 30 gr. 


0.200 to 1 Gm 


3 to 15 gr. 


1 to 2 C. c. 


15 to 30 C. c. 


2 to 8 C. c. 


30 to 120 C. c. 


0.200 to 1 Gm 


3 to 15 gr. 


50 to 600 mGm 


1 to 10 gr. 


1 to 2 Gm 


15 to 30 gr. 


0.05 to 0.30 C. c. 


1 to 5 min. 


5 to 15 C. c. 


1 to 4 fl. dr. 


1 to 4 C. c. 


15 to 60 min. 


0.200 to 1 Gm 


3 to 15 gr. 


0.100 to 0.500 Gm 


2 to S gr. 


0.50 to 2 C. c. 


8 to 30 min. 


2to4C. c. 


30 to 60 min. 



4 o4 



ABOUT DRUGS. 



Remedies. 



Cinchona 

abstr . . . ... 

extr 

inf 

fl. extr 

tinct 

" comp 

Cinchonidina, and salts 
Cinchonina, and salts.,. 

Cinnamomum 

fl. extr 

tinct 

Cocaina and salts 

Cocculus, fl. extr 

Codeina 

Colch. rad 

" extr 

" fl. extr 

" tinct 

" vin 

" sem. fl. extr. 

'• tinct 

" vin 

Colocynthis 

extr 

extr. comp 

fl. extr 

Comptonia, fl. extr 

Condurango, fl. extr.... 
Conhydrine, and salts.. 

Conii fruct 

" abstr 

" extr 

" fl. extr 

" tinct 

herb 

" abstr 

" extr 

" fl. extr 

" tinct.. 

Coniina, and salts 

Convallaria, fl. extr 

Copaiba 

massa 

oleum. c 

resina 

Cornus. fl. extr 

Corydalis, fl. extr 



Single Adult Dose. 



Metric Weights and Measures. 



1 to 4 Gm 
0.500 to 2 Gm 
0.200 to 1 Gm 

15 to 60 C. c. 

2 to 4 C. c. 
4 to 12 C. c. 
4 to 12 C. c. 

0.060 to 2 Gm 
0.060 to 2 Gm 
0.400 to 2 Gm 
0.50 to 1 C. c. 

1 to 5 C. c. 
10 to 60 mGm 

0.05 to 0.50 C. c. 
30 to 100 mGm 
100 to 500 mGm 
30 to 100 mGm 
0.10 to 0.50 C.c. 
0.50 to 2C. c. 
0.50 to 2 C. c. 
0.20 to 0.50 C. c. 
0.50 to 2 C. c. 
0.50 to 2 C. c. 
0.500 to 1 Gm 
100 to 300 mGm 
100 to 300 mGm 
0.50 to 2 C. c. 

2 to 8 C. c. 
0.50 to 2 C. c. 

1 to 3 mGm 
100 to 400 mGm 
60 to *00 mGm 
20 to 60 mGm 
0.06 to 0.30 C. c. 
0.30 to 2 C. c. 
0.300 to 1 Gm 
100 to 500 mGm 
50 to 150 mGm 
0.20 to 1 C. c. 
0.50 to 4 C. c. 
1 to 2 mGm 
1 to 2 C. c. 
1 to4C. c. 

1 to 4 Gm 
0.50 to 1 C. c. 

0.200 to 1 Gm 

2 to 4 C. c. 
l'to 2 C. c. 



Old Apothecaries' 
Weights and Measures. 



15 to 60 gr. 

8 to 30 gr. 

3 to 15 gr. 

\ to 2 fl. ozs. 
30 to 60 min. 

1 to 3 fl. dr. 

1 to 3 fl. dr. 

1 to 30 gr. 

1 to 30 gi . 

6 to 30 gr. 

8 to 15 min. 
15 to 80 min. 

i to 1 gr. 

1 to 8 min. 
| to 2 gr. 

2 to 8 gr. 

1 to 2 gr. 

2 to 8 min. 
8 to i min. 
8 to SO min. 

3 to 8 min. 
8 to 80 min. 
8 to 30 min. 
8 to 1 5 gr. 

2 to h gr. 
2 to 5 gr. 
8 to 30 min. 
| to 2 fl. dr. 
8 to 30 min. 
it to ¥o gr. 
2 to (J gr. 
1 to 3 gr. 
i to 1 gr. 

1 to 5 min. 
5 to 30 min. 

4 to 15 gr. 

2 to 8 gr. 
f to 2 gr. 

3 to 15 min. 
8 to 60 min. 

■h to -h gr. 
15 to 30 min. 
15 to 60 min. 
15 to 60 gr. 

8 to 15 min. 

3 to 15 gr. 
30 to 60 min. 
15 to 30 min. 



ABOUT DRUGS. 



405 



Remedies. 



Coto 

abstr 

extr . . . 

fl.extr 

tinct 

Cotoinum 

Creasotum 

aqua 

Creta 

mist. i 

pulv. comp 

Crocus 

tinct 

Croton-chloral 

Cubeba 

fl. extr 

oleum 

oleores 

tinct 

Cupri acet 

sulph 

Cuprum ammon 

Curare 

Curarina 

Cypriped, fl. extr 

Damiana, fl. extr 

Daturina 

Delphin. , fl. extr 

Digitalinum 

Digitalis 

abstr 

extr 

fl. extr 

infus 

tinct 

Dioscorea, fl. extr 

Dracont. , fl. extr 

Drosera, fl. extr 

Duboisina, and salts 

Dulcamara, extr 

fl extr 

Elaterin (U. S. P., 1880).. . 

tritur 

Elaterium (U. S. P., 1870)... 
Emetina, and salts, diaphor. 
" " emet . . . 
Ergota 

extr 



Single Adult Dose. 



\Tetric Weights and Measures 



0.200 

100 

50 

0.20 

1 

10 

0.05 

4 

1 

30 

0.500 

0.300 

4 

0.200 

1 

1 

50 

0.50 

4 

30 
30 
10 
2 
1 
1 
2 

0.50 

0.06 

1 

50 

30 

10 

0.20 

10 

0.30 

1 

2 

0.50 

0.50 

0.300 

4 

1 

10 

4 

0.50 

8 

1 

0.200 



o 1 Gm 
o 500 mGm 
o 200 mGm 
o 1 C. c. 
o 4 C. c. 
o 30 mGm 
o 0.20C. c. 
o 15 C. c. 
o 5 Gm 
o 60 C. c. 
o 2 Gm 
o 2 Gm 
o 8 C. c. 
o 1 Gm 
o 4 Gm 
o2 C.c 
o 1 C. c. 
o 2 C. c. 
08C. c. 
o 200 mGm 
o 500 mGm 
o 60 mGm 
o 10 mGm 
o 3 mGm 
o4C. c 
olOC. c. 
o 1 mGm 
o0.20C. c. 
o 2 mGm 
o 200 mGm 
o 100 mGm 
o 30 mGm 
o2C. c. 
o 20 C. c. 
o 4 C. c. 
o2C. c. 
o4C. c. 
o 1 C. c. 
b 1 mGm 
o 1 Gm 
08 C. c. 
o 4 mGm 
o 40 mGm 
o 30 mGm 
o 2 mGm 
o 15 mGm 
o 4 Gm 
o 1 Gm 



Otd Apothecaries' 1 
Weights and Measures. 



33 

1 
6T 

15 
30 

lis 
1 



5 
1 

1 

6 

tV 

T"2~8 



o 15 gr. 
o 8 gr. 
o 3_gr. 
o 15 min. 
o 60 min. 
j gr. 
o 3 min. 
o 4 fl. dr. 
o 80 gr. 
o 1 fl. dr. 
o 30 gr. 
o 30 gr. 
o 2 fl. dr. 
o 15 gr. 
o 60 gr. 
o 30 min. 
o 15 min. 
o-30 min. 
o 2 fl. dr. 
o3gr. 
o 8 gr. 
o 1 gr. 
oigr. 

°-fa g r - 
o 60 min. 
o 150 min. 

o ei g r - 
o 8 min. 
o sV gr. 
o 3 gr. 
o 2 gr. 
o£gr- 
o 30 min. 
o 5 fl. dr. 
o 60 min. 
o 30 min. 
o 60 min. 
o 15 min. 

o A g r - 
o 15 gr. 
o 2 fl. dr. 

o tV g r - 
ofgr. 

°igr- 
o 3V gr. 
o Jrgr. 
o 60 gr. 
o 15 gr. 



4c6 



AEOUT DRUGS. 



Single Adult Dose. 



Remedies. 



Metric \Veighis and Measures. 



Old Apothecaries' 1 
Weights and Measures. 



Ergota fl. extr 

tinct 

vin 

Ergotinum 

Erigeron, fl. extr 

oleum 

Eriodictyon, fl. extr 

Ervthroxylon, fl extr 

Eserina, and salts 

Eucalyptus, fl. extr 

oleum 

Euonymus, extr 

fl'. extr 

Exalgin 

Extracts, see each drug. 

Fel bovis purif 

Ferri acet. tinct 

arsen 

benzoas 

brom 

" syr 

carb. sacch , 

" massa 

chlorid 

chlorid. liqu , 

tinct 

citr 

" liqu 

" vin 

et ammon. citr , 

et " sulph.... 

et " tartr 

et cinch, citr 

et pot. tart , 

et quin. citr , 

et strych. citr 

extr. pom 

ferrocyanid , 

h}-pophosphis 

syr.... 

iodid 

" Pil 

" sacch 

" syr 

lactas 

liquor dialys 

mist, comp 

nitr. liqu 

oxalas 



1 to 
4 to 
4 to 
0.200 to 
4 to 
0.30 to 

1 to 

2 to 
1 to 
1 to 

0.60 to 

200 to 

1 to 

250 to 



8 C. c. 
15 C. c. 
15 C. c. 
1 Gm 



u. c. 

C. c. 

C. c. 

C. c. 

mGm 

C. c. 

C. c. 
500 mGm 
4C. c. 
500 mGm 



200 

1 

6 

60 

60 

0.50 

250 

0.250 

50 

0.10 

1 

300 
0.60 

300 
300 

0.500 
100 

0.500 
100 
60 
250 
200 
250 

30 

1 

120 

1 

100 

0.50 



200 



to 400 mGm 
to 2 C. c. 
to 60 mGm 
to 300 mGm 
to 300 mGm 
to 3 C. c. 
to 1 Gm 
to 1 Gm 
to 200 mGm 
to 0.60 C. c. 
to 2 C. c. 
to 600 mGm 
to 1 C. c. 

4C. c. 
to 600 mGm 
to 600 mGm 
to 2 Gm 
to 500 mGm 
to 2 Gm 
to 500 mGm 
to 200 mGm 
to 500 mGm 
to 400 mGm 
to 500 mGm 

4C. c. 
to 150 mGm 
to 5 pills 
to 500 mGm 
to 4 C. c. 
to 500 mGm 
to 2 C. c. 
to 30 C. c. 

0.50 C. c. 
to 300 mGm 



15 min. 

1 

1 

3 

1 

. 5 

15 

30 

15 

10 
3 

15 
4 

8 

15 

i 

10 

1 
1 
8 
4 
4 
1 
2 

15 
5 

10 

5 
5 
8 
2 
8 
2 
1 
4 



2 fl. dr. 
o 4 fl. dr. 
o4fl. dr. 
o 15 gr. 
o 2 fl. dr. 
o 15 min. 
o 30 min. 
o 60 min. 
o ^o gr. - 
o 60 min. 
o 30 min. 
o 8gr. 
o 60 min. 
o 8 gr. 



3 to 



6 gr. 
30 min. 
Igr- 
5 gr. 

5 gr. 
45 min. 
15 gr. 
15 gr. 

3 gr. 
10 min. 
30 min. 
10 gr. 
15 min. 
1 fl. dr. 
10 gr. 
10 gr. 
30 gr. 
8gr. 
30 gr. 
8gr. 
3gr. 
8gr. 

6 gr. 
8gr. 

1 fl. dr. 
2gr. 
5 pills 
8gr. 
60 min. 
8gr. 
30 min. 
8 fl. dr. 
8 min. 
5 gr. 



Remedies. 



-,z:v: z?.v :- ; . 



Ferri oxid. hydra: 

magnet 

'* sacch 

" " syi 

pil. comp 

phosphas, 1870 

phosphas, 1880 

pom. tinct 

pyrophosphas 

subcarb 

sulph 

:xsicc 

valer 

vin. amar 

" dulc 

Ferrum dialysat 

reductum 

Fr-mcma. :■::: 

fl. ex:r 

Fluid extrs. , see each drug. . 

Fuchsin 

Galbanum 

pil. comp 

Galla 

tinct 

Gelsemium 

abstr 

extr 

fl. extr 

tinct 

Gentiana extr 

- t:::: 

inf. comp 

tinct 

" comp 

Geranium, fl. extr 

Glonoin. 1 per cent. sol. .. 
Glycyrrhiza. pulv. comp. . . 

s s pium, fl. ex:r 

Granatum 

decoct 

\: 

f. -.-- 

Grindelia. fl. extr 

Guaiari Hgn 

fl. ex:r 

resina 

•' tinct 

" " a mm or. 



! : X I : 

lto 

20v :-- 

2i0 :: 

1 to 

2.>. :: 

?■■:>.<■-. 

I'!"' :: 
"■0 :: 
SOU 



: r tc 
BO tc 
2 ; i 
2 to 

60 to 

0.5:': :: 

a 

2 to 

10 :: 

60 to 

2'. : 

~ I 

a 

15 to 
2 tc 

2tc 

: i 

2 :: 

2 tt 

2 I 

60 to 

o.o •: -.- 
a i 

2 to 

2 to 

0.500 to 

2 to 

O -- 



1 r ::. 
4C. c. 

~ ~: .5 
£'": m.Gm 

• ■: : mGm 

2 C. c. 

: : : m :-~ 

'■':■'.■ m --:. 
'-' m G " 

: ~ :,r.-. 

2 : ~j- 
4 C. c. 
4C. c. 

2 C. c. 

i 

: mGm 
6C. c. 

900 mGm 
1 Gm 

3 cms 
1 Gm 

4 C :. 
3 

2: : - 
60 mGm 
KS C. c. 
a C. : 
1 Gm 
4C. c. 

: c 

5 C c. 
- C. :. 
4C. c. 

C. c. 

4 Gm 
4C. c. 

5 Gm 

: X C. c. 

1 Gm 

4C. c. 
~ C. c. 
5 Gm 
4C. c. 
1 Gm 
4C. c. 
4C. : 



to 
5 to 
5 to 

lto 
3 to 

3 to 

3:o 

4 to 
2 :: 

1 to 
1 to 



5 :: 
lto 
3 to 



- ?r 

:: - 

1 i ir. 
4 pills 
5gr. 

gr 

. mm. 
: ir 
8gr. 
4gr. 

2 gi 

3 ST. 

1 ~. ir. 

1 fl. dr. 

c : -ir.. 

5gr. 

8gr. 

2 f ir. 



1 to £ gi 

6 to 16 gr. 

. - : - = 

S :o 16 gr. 

:-:: :: •; . mm. 

2 : c S ; r 

1 to 4 gr. 
i to 1 gr. 

2 to 8 min. 
M : c : ; 

3 to 15 gr. 
?■'_> :: ■?. mm. 

| to 1 fl. oz. 

i to 2 fl. dr. 

£ to 2 fl. dr. 
15 to 60 min. 
^ min.— 
30 to 60 gr. 
\ o : : ■:' ' mm. 
30 :: r ~. 

2 to 4 fl. ozs. 

8 to 15 gr. 
30 to 60 min. 
SO :: Ov mm 
10 to 80 gi 
m :: •: ' mm. 

8 to 16 gr. 
30 to 60 rain. 
: : : mm 



40 8 



ABOUT DRUGS. 



Remedies. 



Metric. Weights and Measures, 



Guaiacol 

Guarana 

fl. extr 

Hsematoxylon, decoct 

extr 

fl. extr 

Hamamelis, fl. extr 

Helleb nig., extr 

fl. extr 

tinct 

Homatropina, hydrobrom 
Humulus, extr 

fl. extr 

tinct 

Hydrangea, fl. extr 

Hydrarg. chlorid. corros. 
" mite... 

cyanid 

iodid flav 

"*' rubr 

" vir 

massa 

oxid. flav . . . 

" nigr 

" rubr. 

Pil 

subsulph. flav 

c. creta 

salicylas 

ungu 

Hydrastis 

extr 

fl. extr 

tinct 

Hydroquinone 

Hyoscina, and salts 

Hyoscyamina, and salts.. 
Hyoscyamus 

abstr 

extr 

fl. extr 

tinct 

Hypnone 

Hypophosphitum syr. . . . 

Ichtyol 

Ignatia 

abstr 

extr 



Single Adult Dose. 



0.06 C. 


c. 


1 


to 


4 Gm 


2 


to 


4C. c. 


30 


to 


60 C. c. 


250 


to 


600 mGm 


2 


to 


4 C. c. 


4 


to 


8 C. c. 


50 


to 


200 mGm 


0.20 to 1 C. c. 


1 


to 


4 C. c. 


0.30 


to 


1 mGm 


60 


to 


300 mGm 


2 


to 


4 C. c. 


4 


to 


8C. c. 


2 


to 


4C. c. 


4 


to 


6 mGm 


0.005 


to 


1 Gm 


4 


to 


15 mGm 


4 


to 


50 mGm 


3 


to 


8 mGm 


4 


to 


50 mGm 


0.120 


to 


1 Gm 


3 


to 


5 mGm 


3 


to 


5 mGm 


3 


to 


5 mGm 


0.250 


to 


1 Gm 


60 


to 


120 mGm 


30 


to 


750 mGm 


60 


m 


Gm 


0.250 


to 


1 Gm 


0.500 


to 


2Gm 


100 


to 


300 mGm 


0.50 


to 


2C. c. 


2 


to 


8C. c. 


100 


to 


600 mGm 


0.10 


to 


0.50 mGm 


0.30 


to 


1 mGm 


200 


to 


500 mGm 


60 


to 


300 mGm 


30 


to 


200 mGm 


050 


to 


2 C. c. 


2 


to 


8 C. c. 


0.06 C 


c. 


4C 


c. 


025 


to 


1.30 C. c. 


50 


to 


200 mGm 


30 


to 


120 mGm 


15 


to 


30 mGm 



Old Apothecaries'* 
Weights and Measures. 



1 min. 
15 to 60 gr. 
30 to 60 min. 

1 to 2 fl. ozs. 

4 to 10 gr. 
30 to 60 min. 

1 to 2 fl. dr. 

1 to 3 gr. 

3 to 15 min. 
15 to 60 min. 

irio to <?o g r - 
1 to 5 gr. 
30 to 60 min. 

1 to 2 fl. dr. 
30 to 60 min. 

it to to g r - 
T V to 15 gr. 
tV to i gr. 
T5 to 1 gr. 
20 to | gr. 
T§ to 1 gr. 

2 to 16 gr. 
A to T V gr. 
20 to T V gr. 
20 t° T3 gr- 

4 to Iti gr. 

1 to 2 gr. 
i to 12 gr. 
Igr. 

4 to ±6 gr. 
8 to 30 gr. 

2 to 5 gr. 

8 to 30 min. 
i to 2 fl. dr. 

2 to 10 gr. 
ek to % fa gr. 
2 fa to 6T gr. 

3 to 8 gr. 
1 to 5 gr. 
i to 3 gr. 

8 to 30 min. 
\ to 2 fl. dr. 
1 min. 
1 fl. dr. 

4 to 20 min. 
1 to 3 gr. 

% to 2 gr. 
i to % gr. 



ABOUT DRUGS. 



409 



Remedies. 



Single Adult Dose. 



Metric Weights and Measures, 



Ignatia, fl. extr 

tinct 

Iodoformum 

Iodol 

Iodum 

liquor, com 

tinct 

Ipecac, expect 

emet 

abstr. expect 

emet. 

et opii pulv 

" " tinct 

fl. extr., expect.. . 
" emet 

syr. expect 

*' emet 

vin. expect 

" emet 

Iris versicolor, extr. . . 

fl. extr 

Jalapa 

abstr 

extr. B. P 

" ale 

fl. extr 

pulv. comp 

resina 

tinct 

Juglans, extr 

fl. extr. 

Juniperus, fl. extr 

Kairina 

Kamala 

fl. extr 

Kino 

tinct 

Krameria, ext 

fl. extr 

s y r 

tinct 

Lactuca, extr 

fl. extr. 

Lactucarium 

fl. extr 

syr 

Lavand., tinct. comp. 
Leonurus, fl. extr 



0.05 to 0.20 C. c. 
1 to 4 C. c 
50 to 200 mGm 
60 to 120 mGm 
5 to 20 mGm 
0.20 to 0.50 C. c. 
.30 to 1.30 C. c. 
10 to 60 mGm 
1 to 2 Gm 
5 to 30 mGm 
0.500 to 1 Gm 
200 to 600 mGm 
0.20 to 60 C. c. 
0.10 to 60 C. c. 

1 to 4 C. c. 
0.60 to 2 C. c 

4 to 15 C. c. 
0.30 to 1 C. c. 

10 to 25 C. c. 
200 to 300 mGm 
1 to 2 C. c. 
1 to 2 Gm 
500 to 1 Gm 
0.500 to 1 Gm 
200 to 400 mGm 

1 to 2 C. c. 
0.500 to 2 Gm 

120 to 300 mGm 
4 to 10 C. c. 
0.500 to 2 Gm 
4 to 8 C. c. 

2 to 4 C. c. 
0.400 to 1.300 Gm 

4 to 8 Gm 

4 to 8 C. c. 
0.500 to 1 Gm 

2to8C. c. 
250 to 1 Gm 

2 to 4 C. c. 

4 to 15 C c. 

2 to 8 C. c. 
120 to 500 mGm 

1 to 4 C. c. 
0.50 to 4 Gm 
0.30 to 2 C. c 

4 to 15 C. c. 

2 to 4 C c. 
2 to 4 C. c. 



Old Apothecaries' 
Weights and Measures. 



1 


to 


3 min. 


15 to 60 min. 


1 


to 


3 gr. 


1 


10 


2gr. 


tV 


to 


igr. 


3 


to 


8min. 


5 


to 


20 mm. 


1 

6 


to 


Igr. 


15 


to 


30 gr. 


1 


to 


igr. 


8 


to 


15 gr. 


3 


to 


10 gr. 


3 


to 


10 min. 


1 


to 


1 min. 


15 to 60 min. 


10 


to 


30 min. 


1 


to 


4 fl. dr. 


5 


to 


15 min. 


3 


to 


-6 fl. dr. 


3 


to ?r. 


15 


to 


30 min. 


15 to 3D gr. 


8 


to 


15 sr. 


8 


to 


15 gr. 


3 





6 gr. 


15 


to 


30 min. 


8 


to 


30 gr. 


2 


to 


5 gr. 


1 


to 


21 fl. dr. 


8 


to 


30 gr. 


1 


to 


2 fl. dr. 


30 


to 


60 min. 


6 


to 


20 gr. 


1 


to 


2 dr. 


1 


to 


2 fl. dr. 


8 


to 


15 gr. 


' * 


to 


2 fl. dr. 


4 


to 


15 gr. 


30 


to 


60 min. 


1 


to 


4fl. dr. 


1 
2 


to 


2 fl. dr. 


2 to 8gr. 


15 to 


61J min. 


8 


to 


60 gr. 


5 


to 


30 min. 


1 


to 


4fl dr. 


30 


to 


60 min. 


30 


to 


tO min. 



4io 



ABOUT DRUGS. 



Remedies. 



Leptandra 

extr 

fl. extr 

Liqu. acidi arsen , 

ammon. acet. 
arseni et hydr. iod. 

ferri acet 

" chlor 

" citr 

" dialys 

" nitrat 

pepsini 

potassae 

pot arsenit 

" citr 

sodae 

sodii arseniat 

Lithii benzoas 

brom 

carb 

chlorid 

citr 

salicyl 

Lobelia, acet 

fl. extr 

tinct 

Lupulinum 

fl. extr 

oleores 

tinct 

Magnesia 

Magnes. carb 

citr. granul 

et asaf. mist 

sulphas 

sulphis . .... 

Maidis stigm., fl. extr. 

Mangani sulph 

Marina 

Massa copaibae 

ferri carb 

hydrarg 

Matico, fl. extr 

tinct 

Mentha pip., oleum. . . 

spir 

Methacetin 

Methylal 



Single Adult Dose. 



Metric Weights and Measures. 



1 to 2 Gm 
50 to 200 mGm 
1 to 2 C. c. 
0.10 to 0.50 C. c. 
4 to 30 C. c. • 
0.10 to 0.50 C. c. 
0.10 to 0.50 C. c. 
0.10 to 0.60 C. c. 
0.50 to 1 C. c. 
0.50 to 2 C. c. 
0.50 to 1 C. c. 
8 to 15 C. c. 
0.30 to 2 C. c. 
0.10 to 50 C c. 

8 to 15 C. c. 

0.30 to 2 C. c. 

0.10 to 0.50 C. c. 

100 to 300 mGm 

60 to 200 mGm 

100 to 400 mGm 

100 to 300 mGm 

100 to 300 mGm 

100 to 500 mGm 

1 to 4 C. c. 
0.20 to 2 C. c. 
50 to 4 C. c. 

0.300 to 1 Gm 
0.30 to 1 C. c. 
100 to 250 mGm 

2 to 8C. c. 
0.50 to 2 Gm 

1 to 5 Gm 
8 to 30 Gm 
4 to 15 C. c. 
8 to 30 Gm 
1 to 2 Gm 
4C. c. 
100 to 500 mGm 
30 to 60 Gm 

1 to 4 Gm 
0.250 to 1 Gm 
0.120 to 1 Gm 

2 to 4 C. c. 
4 to 15 C. c. 
1 to 3 drops 

30 to 1 C. c. 
200 to 500 mGm 
1 to 2 C. c. 



Old Apothecaries'" 
Weights and Measures. 



15 to 30 gr. 

1 to 6 gr. 
15 to 30 min. 

2 to 8 min. 

1 to 8 fl. dr. 

2 to 8 min. 
2 to 8 min. 
2 to 10 min. 
8 to 15 min. 
8 to 30 min. 
8 to 15 min. 
2 to 4 fl. dr. 
5 to 30 min. 
2 to 10 min. 
2 to 4 fl. dr. 
5 to 30 min. 

2 to 8 min. 
1 to 5 gr. 

1 to 3 gr. 
1 to 6 gr. 
1 to 5 gr. 
1 to 5 gr. 

1 to 8 gr. 
15 to 60 min. 

3 to 30 min. 
8 to 60 min. 
5 to 15 gr. 

5 to 15 min. 

2 to 4 gr. 

\ to 2 fl. dr. 

8 to 30 gr. 
15 to 80 gr. 

-|- to 1 oz. 

1 to4fl. dr. 

\ to 1 oz. 
15 to 30 gr. 

1 fl. dr. 

2 to 8 gr. 

1 to 2 ozs. 
15 to 60 gr. 

4 to 16 gr. 

2 to 16 gr. 
30 to 60 min. 

1 to 4 fl. dr. 
1 to 3 drops 

5 to 15 min. 

3 to 8 gr. 

15 to 130 min. 



ABOUT DRUGS. 



411 



Remedies. 



Methysticu'm, fl. extr 

Mezereum, fl. extr 

Mist, ammon 

asafoet 

chloroformi 

cretse comp 

ferri comp 

ferri et ammon. acet. . . . 

glycyrrh. comp 

magnes. et asaf 

pot. citr 

rhei et sodae 

Morphina and salts 

pulv. comp 

Moschus 

tinct 

Myrica 

fl. extr 

Naphthalin 

Narceina 

Narcotina 

Nitroglycerin, 1 per cent. sol. 
Nux Vomica 

abstr 

extr 

fl. extr 

tinct 

Oleoresina aspidii 

capsici 

cubebae 

lupulini 

piperis 

zingiberis 

Oleum anisi 

cajuputi 

cari 

chenopodii 

copaibaa 

cubebae 

erigerontis 

eucalypti 

foeniculi 

menthae pip 

morrhuae 

olivae 

phosporat , 

ricini 

sabinae • 



Single Adult Doses. 



Metric Weights and Measures , 



1 to 4 C. c. 
0.30 to 1 C. c. 
15 to 30 C. 
15 to 30 C. 

5 to 15 C. 
30 to 60 C. 

4 to 30 C. 

8 to 15 C. 

4 to 15 C. 

4 to 15 C. 

8 to 30 C. c. 

8 to 30 C. c. 

4 to 30 mGm 
0.500 to 1 Gm 
0.100 to 1 Gm 

1 to 8 C. c. 

2 to 4 Gm 
2 to 4 C. c. 

0.300 to 2 Gm 
10 to 30 mGm 
20 to 60 mGm 

1 drop 
50 to 300 mGm 
30 to 120 mGm 
15 to 60 mGm 

0.05 to 0.30 C. c. 

0.30 to 1.30 C. c. 
1 to 4 Gm 
10 to 30 mGm 
0.500 to 2 Gm 

100 to 250 mGm 
60 to 200 mGm 
60 to 200 mGm 

0.20 to 0.50 C. c. 

0.10 to 0.50 C. c. 

0.10 to 0.50 C. c. 

0.25 to 0.50 C. c. 

0.50 to 1 C. c. 

0.50 to 1 C. c. 

0.30 to 1 C. c. 

60 to 2 C. c. 

0.20 to 0.50 C. c. 

1 to 3 drops 
15 C. c. 

15 to 60 C. c. 

0.06 to 0.20 C. c. 

8 to 30 C. c. 

2 to 5 drops 



Old Apothecaries'* 
Weights and Measures. 



dr. 

dr. 

ozs. 

dr. 



15 to 60 min, 
5 to 15 min. 
4 to 8 fl. dr. 

4 to 8 fl. 
1 to 4 fl. 
1 to 2 fl. 

1 to 8 fl. 

2 to 4 fl. dr. 
1 to 4 fl. dr. 

1 to 4 fl. dr. 

2 to 8 fl. dr. 
2 to 8 fl. dr. 

ye to \ gr. 
8 to 15 gr. 
\\ to 15 gr. 
15 to 120 min. 
30 to 60 gr. 
30 to 60 min. 

5 to 30 gr. 
\ to \ gr. 
\ to 1 gr. 
1 drop 

1 to 5 gr. 
I to 2 gr. 
i to 1 gr. 

1 to 5 min. 
5 to 20 min. 

15 to 60 gr. 
i to \ gr. 
8 to 30 gr. 

2 to 4 gr 
1 to 3 gr. 
1 to 3 gr. 

3 to 8 min. 
1 to 8 min. 
1 to 8 min. 

4 to 8 min. 
8 to 15 min. 
8 to 15 min. 

5 to 15 min. 
10 to 30 min. 

3 to 8 min. 
1 to 3 drops 
^fl. oz. 
\ to 2 fl. ozs. 
1 to 3 min. 

1 to 1 fl. oz. 

2 to 5 drops 



4 I2 



ABOUT DRUGS. 



Remedies. 



Oleum, santali 

terebinth 

tiglii 

valer 

Opium 

acet 

extr 

Pil.(lgr-) 

tinct 

" camph 

" deod 

vin 

Pancreatin 

Papa ; n 

Papaver, extr 

fl. extr 

Paraldehyd 

Pareira, fl. extr 

Pelletierin tannate 

Pepsin, pure (2,000) 

liquor 

sacch. (50) 

Phenacetin 

Phosphorus 

oleum 

pil 6 

Physostigma 

abstr 

extr 

fl. extr 

tinct 

Physostigmina, and salts. . . 
Phytolacca, bacca., fl. extr. . 

rad 

" abstr 

" extr 

" fl. extr 

" tinct 

Picrotoxin 

Pilocarpina, and salts 

Pilocarpus 

abstr 

extr 

fl. extr 

Pilutse aloes 

" et asafoet 

" et ferri 

' ; et mast 



Single Adult Dose. 



Metric Weights and Measures. 



Old Apothecaries^ 
Weights and Measures. 



0.50 to 

0.30 to 

ito 

1 to 
30 to 

0.30 to 
15 to 

0.30 to 

4 to 

0.30 to 

30 to 

100 to 

60 to 

60 to 

2 to 
2 to 
2 to 

0.2OO to 

60 to 

4 to 

0.100 to 

0.200 to 

0.60 to 

0.06 to 

30 to 
15 to 

4 to 
0.05 to 

1 to 
0.60 to 
0.50 to 

50 to 

30 to 

20 to 

0.50 to 

2 to 
0.50 to 

5 to 
2 to 

1 to 
100 to 

2 to 

1 to 

2 to 
1 to 
1 to 



2C. c. 

1 C. c. 

2 drops. 
2 drops. 
60 mGm 
0.60 C. c. 
30 mGm 

1 pill. 
0.60 C. c. 
15 C. c. 
0.60 C. c. 
0.60 C. c. 
300 mGm 
250 mGm 



300 
8C. 
4C. 
4C. 



mGm 



c. 
c. 

500 Gm 
120 mGm 
15 C. c. 
10 Gm 

1 Gm 

1 20 mGm 
0.20 C. c. 

1 pill 

60 mGm 
30 mGm 
10 mGm 
0.20 C. c. 
2C. c. 
1.20 mGm 

2 C. c 
350 mGm 
200 mGm 
150 mGm 
2C c. 

8 C. c. 

1 mGm 
20 mGm 

4 Gm 

2 Gm 
500 mGm 
4C. c. 

3 pills 

5 pills 
3 pills 
3 pills 



8 to 
5 to 



ito 
1 

1 



to 
_ to 
5 to 
ito 

5 to 

1 to 
5 to 
5 to 

2 to 
1 to 
Ito 
ito 
ito 
ito 

3 to 
1 to 

1 to 

2 to 

3 to 

TM to 
1 to 

ito 
fto 

A to 

1 to 
15 to 

tM° 
8 to 

1 to 
ito 
ito 
8 to 
ito 

T¥8 tO 
T L t O 

30 to 
15 to 

2 to 
30 to 

1 to 

2 to 
1 to 
1 to 



30 min. 
15 min. 
2 drops 
2 drops 
Igr. 
10 min, 
igr. 
1 pill 
10 min. 

4 fl. dr. 
10 min. 
10 min. 

5 gr. 
4gr. 
5gr. 

2 fl. dr. 
1 fl. dr. 
1 fl. dr. 
8gr. 
2gr. 

4 fl. dr. 
150 gr. 
15 gr. 

To g r - 

3 min. 
1 pill 

1 gr. 
igr. 
igr- 

3 min. 
30 min. 

fo gr. 
30 min. 

6 gr. 
3 gr. 

2 gr. 
30 min. 
2fl. dr. 
-h g r - 
igr- 
60 gr. 
30 gr. 
8gr 

60 min. 

3 pills 

5 pills 
3 pills 
3 pills 



ABOUT DRUGS. 



413 



Remedies. 



Pilulae aloes et myrrhse 

antim. comp 

asafoetidae 

cathart. comp 

copaibae 

ferri carb 

" comp 

galbani comp 

hydrarg 

opii (1 gr.) 

phosphori 

rhei 

" comp 

Piper 

oleoresina 

Piperina 

Piscidia, fl. extr 

Plumbi acet 

iod . 

Podophyllum 

abstr 

extr 

fl. extr 

resina 

tinct 

Populin 

Populus, fl. extr 

Potassa sulphurata. . . . 

Potassae liquor 

Potassii acet 

arsenit. liquor 

bicarb 

bichrom. . 

bitartr 

bromid 

carb 

chloras 

citraa 

cyanid 

et sodii tartr 

hypophosph 

iodid 

nitras 

nitris 

sulphas 

sulphid 

sulphis 

tartras 



Single Adult Dose. 



Metric Weights and Measures. 



Old Apothecaries' 1 
Weights and Measures. 



2 to 
1 to 
1 to 
1 to 

1 to 
250 to 

2 to 
1 to 

0.129 to 

1 to 

2 to 
2 to 

0.300 to 
15 to 
60 to 

1 to 
50 to 
30 to 

300 to 

100 to 

60 to 

0.50 to 

10 to 

2 to 
60 to 

2 to 

60 to 

0.50 to 

0.500 to 

0.10 to 

1 to 

4 to 

1 to 

0.500 to 

0.500 to 

1 to 

8 to 

0.500 to 

0.120 to 

1 to 

120 to 

1 to 

30 to 

1 to 

4 to 



pins 
pills 
pills 
pills 
Gm 
Gm 
pills 
pills 
1 Gm 

1 pill 

2 pills 
5 pills 
5 pills 
1.300 Gm 
60 mGm 
500 mGm 
2 C. c. 
250 mGm 
250 mGm 
600 mGm 
250 mGm 
200 mGm 
1.50 C. c. 
30 mGm 
4 C. c. 
300 mGm 
4 C. c. 
250 mGm 
2 C. c. 

1 Gm 
0.50 C. c. 
2gr. 
10 mGm 
8 Gm 
8Gm 
1 Gm 

1 Gm 

2 Gm 

8 mGm 
30 Gm 
2 Gm 

1 Gm 
15 Gm 
200 mGm 
10 Gm 
200 mGm 

2 Gm 
15 Gm 



2 to 5 pills 
1 to 3 pills 
1 to 6 pills 
1 to 4 pills 
15 to 60 gr. 



1 

15 gr. 

8 

8 

15 



2 

15 gr. 

2 

15 

i 
15 

1 



to 5 pills 
to 5 pills 
to 15 gr. 
1 pill 
to 2 pills 
to 5 pills 
to 5 pills 
to 20 gr. 
to 1 gr. 
to 8 gr. 
to 30 min. 
to 4 gr. 
to 4 gr. 
to 10 gr. 
to 4 gr. 
to 3 gr. 
to 20 min. 
to i gr. 
to 60 min. 
to 5 gr. 
to 60 min. 
to 4 gr. 
to 30 min. 
to 15 gr. 
to 8 min. 
to 30 gr. 

her. 

to 2 dr. 
to 2 dr. 
to 15 gr. 
to 15 gr. 
to 30 gr. 

igr- 
to 1 oz. 
to 30 gr. 
to 15 gr. 
tc 4 dr. 
to 3 gr. 
to 150 gr. 
to 3 gr. 
to 30 gr. 
to 4 dr. 



414 



ABOUT DRUGS. 



Remedies. 



Primus virg., inf.. 

fl. extr 

syr 

Pulvis antimonialis. . . 

aromat 

" fl. extr 

cretae comp 

glycyrrh. comp. . 

ipecac et opii 

jajapse comp 

morph. comp 

rhei comp 

Pyrocatechin 

Quassia, extr 

fl. extr. . 

tinct 

Quercus, fl. extr 

Quinidina, and salts.. 
Quinina, and salts. . . . 
Quininae arsenas . . 
Resina copaibae 

cubebae 

jalapae 

podophylli 

scammonii 

Resorcin 

Rhamnus cath., fl. extr 

pursh., extr 

fl. extr 

Rheum 

extr 

fl. extr 

et sodae mist 

Pil 

" comp 

pulv. comp 

syr 

" arom 

tinct 

'• arom 

" dulc -.. 

yin 

Rhus glabra, fl. extr.. 

Rosa, fl. extr 

Rubus, fl. extr 

syr 

Rumex, fl. extr 



Single Adult Dose. 



Metric Weights and Measures. 


Old Apothecaries'' 
Weights and Measures. 


30 to 60 C. c. 


1 to 2 fl. ozs. 


2 to 4 C. c. 


30 to 60 min. 


8 to 30 C. c. 


\ to 1 fl. oz. 


150 to 600 mGm 


2 to 10 gr. 


0.500 to 2 Gm 


8 to 30 gr. 


0.50 to 2 C. c. 


8 to 30 min. 


0.500 to 2 Gm 


8 to 30 gr. 


2 to 4 Gm 


30 to 60 gr. 


0.300 to 1 Gm 


5 to 15 gr. 


2 to 4 Gm 


30 to 60 gr. 


0.500 to 1 Gm 


8 to 15 gr. 


2 to 4 Gm 


30 to 60 gr. 


120 to 600 mGm 


2 to 10 gr. 


60 to 300 mGm 


1 to 5 gr. 


1 to 4 C. c. 


15 to 60 min. 


4 to 8 C. c. 


1 to2fl dr. 


2 to 4 C. c. 


1 to 2 fl. dr. 


0.050 to 2 Gm 


1 to 30 gr. 


0.050 to 2 Gm 


1 to 30 gr. 


6 to 30 mGm 


tV to \ g r - 


100 to 600 mGm 


2 to 10 gr. 


100 to 600 mGm 


2 to 10 gr. 


100 to 300 mGm 


2 to 5 gr. 


6 to 30 mGm 


Totoi gr> 


100 to 300 mGm 


2 to 5 gr. 


0.300 to 2 Gm 


5 to 30 gr. 


2 to 4 C. c. 


30 to 60 min. 


200 to 500 mGm 


3 to 8 gr. 


2 to 8 C. c. 


30 to 120 min. 


0.500 to 2 Gm 


8 to 30 gr. 


0.300 to 1 Gm 


5 to 15 gr. 


2 to 8 C. c. 


ito 2 fl. dr. 


4 to 30 C. c. 


1 to 8 fl. dr. 


1 to 5 pills 


1 to 5 pills 


1 to 3 pills 


1 to 3 pills 


1 to 4 Gm 


15 to 60 gr. 


4C. c. 


1 fl. dr. 


4C. c. 


1 fl. dr. 


4 to 15 C. c. 


1 io 4 fl. dr. 


4 to 15 C. c. 


1 to 4 fl. dr. 


4 to 15 C. c. 


1 to 4 fl. dr. 


4 to 15 C. c. 


1 to 4fl. dr. 


2 to 4 C. c. 


30 to 60 min. 


2 to 4 C. c. 


30 to 60 min. 


4 to 8 C. c. 


1 to 2 fl. dr. 


8 to 15 C. c. 


2 to 4 fl. dr. 


2 to 4 C. c. 


30 to 60 min. 



ABOUT DRUGS. 



415 



Remedies. 



Sabina, fl. extr 

oleum 

Salicin 

Saloi 

Sanguinaria 

abstr 

acet 

fl. extr 

Sanguinarina, and salts. 
Santonica 

fl. extr 

Santonin 

album 

Sapo 

Sarsap. dec. comp 

fl. ext 

" comp 

syr. " 

Scammonium 

resina 

Scilla 

acet 

fl. extr 

syr 

" comp 

tinct 

Scoparius, fl. extr ...... 

Scutellaria, fl. extr 

Senega 

abstr 

fl. extr 

syr 

Senna 

conf 

fl. extr. 

inf. comp 

syr 

Serpentaria , 

fl. extr 

tinct 

Sodae liquor 

Sodii acet 

arsenas 

benzoas 

bicarb. 

bisulphis 

boras 

bromid 



Single Adult Dose. 



Metric Weights and Measures. 



0.30 

2 

1 

0.300 

0.100 

50 

1 

0.50 

1 

1 

1 

50 

100 

0.300 

90 

4 

2 

4 

0.500 

100 

0.060 

0.60 

0.20 

2 

2 

0.50 

2 

4 

0.500 

200 

0.50 

4 

2 

4 

4 

30 

4 

2 

2 

4 

0.50 

1 

1 

1 

1 

1 

1 

1 



to 1.50 C. c. 
to 5 drops 
to 2 Gm 
to 4 Gm 
to 1 Gm 
to 400 mGm 
to 2 C c. 
to 1 C. c. 
to 3 mGm 
to 4 Gm 
to 2 C. c. 
to 250 mGm 
to 500 mGm 
to 1 Gm 
to 150 C. c. 
to 8 C. c. 
to 8 C. c. 
to 15 C. c. 
to 1 Gm 
to 300 mGm 
to 1 Gm 
to 2 C. c. 
to 1 C. c. 
to 4 C. c. 
to 4 C. c. 
to 2 C. c. 
to 4 C. c. 
to 8 C. c. 
to 1 Gm 
to 500 mGm 
to 1 C. c. 
to 8 C. c. 
to 8 Gm 
to 8 Gm 
to 15 C. c. 
to 60 C. c. 
to 15 C. c. 
to 4 Gm 
to 4 C. c. 
to 8 C. c. 
to 2 C. c 
to 4 Gm 
to 3 mGm 
to 2 Gm 
to 2 Gm 
to 2 Gm 
to 2 Gm 
to 4 Gm 



Old Apothecaries' 1 Weight 
and Measures. 



5 to 20 min. 

2 to 5 drops. 
15 to 30 gr. 

5 to 60 gr. 

2 to 15 gr. 

1 to 6 gr. 
15 to 30 min. 

8 to 15 min. 

is to h S v - 
15 to (5U gr. 
15 to 30 min. 

1 to 4 gr. 

2 to 8 gr. 
5 to 15 gr. 

3 to 5 fl. ozs. 
1 to 2 fl. dr. 
I to 2 fl. dr. 

1 to 4 fl. dr. 
8 to 15 gr. 

2 to 5 gr. 
1 to 15 gr. 

10 to 30 min. 

3 to 15 min. 
30 to 60 min. 
30 to 60 min. 

8 to 30 min. 
15 to 60 min. 

1 to 2 fl. dr. 

8 to 15 gr. 

3 to 8 gr. 

8 to 15 min. 

1 to 2 fl. dr. 
30 to 120 gr. 

1 to 2 dr. 

1 to 4 fl. dr. 

1 to 2 fl. ozs. 

1 to 4 fl. dr. 
30 to 60 gr. 
30 to 60 min. 

1 to 2 fl. dr. 

8 to 30 min. 
15 to 60 gr. 

eV to io S r - 
15 to 30 gr. 
15 to 30 gr. 
15 to 30 gr. 
15 to 30 gr. 
15 to 60 gr. 



416 



ABOUT DRUGS. 



Remedies. 



Sodii carb 

" exsicc 

chloras 

hypophosphis. . . . 

hyposulphis 

iodid 

nitris 

phosph 

salicylas 

santoninas 

sulphas 

sulphis 

valeras 

Sparteina 

Spigelia 

fl. ext 

et senna, fl. extr. 

Spir. setheris 

" comp. . . 
" nitros. . 

ammonias 

arom. . . 

camphorae 

chloroformi 

lavand. comp. . 

menthas pip 

Stillinsda, fl. extr 



Single Adult Dose. 



Metric Weights and Measures. 



comp 



Stramon. 



syr. 
fol., 



extr 

fl. extr 

sem. abstr 

" extr 

fl. extr 

tinct 

Strophantin 

Strophantus, tinct. (10 fc). 

Strychnina, and salts 

Sulfonal 

Sulphur 

Sumbul, fl. extr 

tinct 

Svrup. acidi hydriod 

allii , 

calcii lactophosph 

calcis 

ferri brom 

" iod 



1 to 2 Gm 
0.500 to 1 Gm 
0.500 to 1 Gm 
0.500 to 1 Gm 
0.500 to 1 Gm 
1 to 2 Gm 
100 to 200 mGm 
0.500 to 4 Gm 
0.300 to 2 Gm 
100 to 500 mGm 
8 to 30 Gm 

1 to 4 Gm 
100 to 500 mGm 

15 to 100 mGm 

2 to 4 Gm 
2 to 4 C. c. 
4 to 8 C. c. 
2 to 4 C. c. 
2 to 4 C. c. 
2 to 8 C. c. 

0.50 to 2 C. c. 

1 to 4 C. c. 

0.50 to 2 C. c. 

1 to 4 C. c. 

2 to 4 C. c. 
2 to 4 C. c. 
4to8C. c. 
4 to 8 C. c. 
4 to 15 C. c. 

30 to 60 mGm 
0.10 to 0.50 C. c. 
20 to 60 mGm 
10 to 40 mGm 
0.05 to 0.30 C. c. 
0.50 to 2 C. c. 
0.40 tol mGm 
0.03 to 0.50 C. 
0.40 to 3 mGm 
1 to 3 Gm 
4 to 15 Gm 

1 to 2 C. c. 

2 to 8 C. c. 
1 to 5 C. c. 
4 to 15 C. c. 
4 to 8 C. c. 
1 to 2 C. c. 

1 to4C. c. 
1 to 4 C. c. 



c. 



Old Apothecaries'' 
Weights and Measures. 



15 to 30 gr. 

8 to 15 gr. 

8 to 15 gr. 

8 to 15 gr. 

8 to 15 gr. 
15 to 30 gr. 

2 to 3 gr. 

8 to 60 gr. 

5 to 30 gr. 

2 to 8 gr. 

2 to 8 gr. 
15 to 60 gr. 

2 to 8 gr. 

i to 2 gr. 
30 to 60 gr. 
30 to 60 min. 

1 to 2 fl. dr. 
30 to 60 min. 
30 to 60 min. 
30 to 120 min. 

8 to 30 min. 
15 to 60 min. 

8 to 30 min. 
15 to 60 min. 
30 to 60 min. 
30 to 60 min. 

1 to 2 fl. dr. 

1 to 2 fl. dr. 

1 to 4 fl. dr. 
| to 1 gr. 

2 to 8 min. 
i to 1 gr. 

\ to f gr. 

1 to 5 min. 

8 to 30 min. 
t£o to eV gr- 

\ to 8 min. 

ih to £> & r - 

15 to 45 gr. 

1 to 4 dr. 
15 to 30 min. 
30 to 120 min. 
15 to 80 min. 

1 to 4 fl. dr. 

1 to 2 fl. dr. 
15 to 30 min. 
15 to 60 min. 
15 to 60 min. 



ABOUT DRUGS. 



417 



Remedies. 



Syrup ferri oxi'di sacch. 
" hypophosph 

hypophosphitum. . . 

c ferro 

ipecac 

krameriae 

lactucarii 

rhei 

" arom 

rosae 

rubi 

sarsap. comp 

scillae 

" comp.. ...... 

senegas 

sennas 

Taraxacum, extr 

fl. extr 

Terebene 

Terebinthina 

oleum 

Terpine 

Terpinol , 

Thalline 

Theina, and salts , 

Tiglii oleum 

Tincturae, see drugs .... 
Toxicodendron, fl. extr. 
Trit repens, fl. extr. . . 

Tritur. elaterini 

Urethan. 

Ustilago, fl. extr 

Uva Ursi, fl. extr , 

Valeriana 

abstr 

extr , 

fl. extr 

tinct 

" ammon 

Veratrina 

Veratrum Vir., abstr. . . 

extr 

fl. extr 

tinct , 

Viburnum, fl. extr 

Vina, see drugs , 

Xanthoxylum, fl. extr. . , 
Zingiber , 



Single Adult Dose. 



Metric Weights and Measures. 



2 
2 
4 
4 
4 
4 
4 
4 
2 
1 
4 
4 

0.300 

2 

0.30 

0.500 
0.30 
200 

0.100 
60 
10 

0.06 

4 

8 

0.120 

1 

2 

2 

1 

0.300 

2 

4 

4 

1 

50 

20 

0.10 

0.20 

4 

1 
0.500 



4 C. c. 

4C. c. 

4C. c. 

4C. c. 
o 15 C. c 
o 15 C. c. 
08C. c. 
o 15 C. c. 
o 15 C. c. 
08 C. c. 
08 C. c. 
o 15 C. c. 
o 4 C. c. 
o4C c. 
08C. c. 
o 15 C. c. 
o 1 Gm 
o 8 C. c. 
o 1.30 G. c. 
o 2 Gm. 
olC.c. 
o 600 mGm 

120 mGm 
o 1 Gm 
o 300 mGm 
o 100 mGm 

o0.30 C. c. 
o 15 C. c. 
o 30 mGm. 
o 2 Gm. 
o 4 C. c. 
o 4 C. c. 
o 4 Gm 
o 2 Gm 
o 1 Gm 
o 4 C. c. 
o 8 C. c. 
08 C. c. 
o 6 mGm 
o 250 mGm 
o 60 mGm 
o 0.50 C. c. 
o lC.c. 
08C. c. 

o 2C. c. 

o 2 Gm 



Old Apothecaries' 1 


Weights 


ind Measures. 


1 fl. 


dr. 


1 fl. 


dr. 


lfl. 


dr. 


1 fl. 


dr. 


*to 


4 fl. dr. 


h to 


4 fl. dr. 


1 to 


2 fl. dr. 


1 to 


4fl. dr. 


1 to 


4 fl. dr. 


1 to 


2 fl. dr. 


1 to 


2 fl. dr. 


1 to 


4 fl. dr. 


30 to 


60 min. 


15 to 


60 min. 


1 to 


2fl dr. 


1 to 


4 fl. dr. 


5 to 


15 gr. 


30 to 


120 min. 


5 to 


20 min. 


8 to 


30 gr. 


5 to 


15 min. 


3 to 


10 gr. 



2 to 
1 to 
ito 



2gr. 
15 gr. 
5 gr. 



*gr- 



1 to 5 min. 

1 to 4 fl. dr. 
\ to \ gr. 

2 to 30 gr. 
15 to 60 min. 
30 to CO gr. 
30 to 60 gr. 
15 to 30 gr. 

5 to 15 gr. 
80 to 60 min. 

1 to 2 fl. dr. 

1 to 2 fl. dr. 
tht to T \ gr. 

1 to 4 gr. 

1 to 1 gr. 

1 to 8 min. 

3 to 15 min. 
1 to 2 fl. dr. 

15 to 30 min. 
8 to 30 gr. 



418 



ABOUT DRUGS. 





Single Adult Dose. 


Remedies. 


Metric Weights and Measures. 


Old Apothecaries' 1 
Weights and Measures. 


Zingiber, fl. extr 


0.50 to 2 C. c. 
60 to 200 mGm 

1 to 4 C c. 
50 to 100 mGm 
30 to 100 mGm 
30 to 100 mGm 
60 to 600 mGm 

5 to 10 mGm 

1 to 2 Gm 
60 to 400 mGm 


8 to 30 min. 


oleores 


1 to 3 gr. 


tinct 


Zinci acet 

brom 


1 to 2 gr. 

\ to 2 gr. 

i to 2 gr. 

1 to 10 gr. 
tV to \ gr. 
15 to 30 gr. 

1 to 6 gr. 


iodid 

oxid 


phosphid v 

sulphas, emetic 


valer 



PART IV. 



PHARMACY, 



PART IV. 



PHARMACY. 

CHAPTER LXXVI. 

THE GENERATION AND APPLICATIONS OF HEAT FOR PHARMACEU- 
TICAL PURPOSES. 

1349. The nature and sources of heat have been discusse.d in Chapter 
XV of Part I. Thermometry, the distribution of heat, the expansion of bod- 
ies under the influence of heat, and the relation of heat to the three states of 
aggregation of matter were sufficiently treated of in Chapters XV to XX, 
inclusive. The student is advised to again refer to those chapters at this stage 
of his progress. 

1350. Among the useful effects and applications of heat 

in pharmaceutical operations are these: 1, to dry drugs, chem- 
icals and pharmaceutical preparations; 2, to aid the solution of 
solids; 3, to facilitate the extraction of the soluble constituents 
of drugs by digestion or decoction; 4, to remove albumin from 
solutions of extractive by coagulation; 5, to destroy ferments; 
6, to hasten evaporation; 7, to vaporize substances in distillation 
and sublimation; 8, to accomplish fusion; 9, to effect calcination; 
10, to induce chemical reaction. 

1351. Damaging effects of heat. — Heat is liable to pro- 
duce damaging effects upon drugs, chemicals and pharmaceuti- 
cal preparations under certain conditions. In the presence of 
moisture, heat may induce discoloration, mould, fermentation or 
putrefaction, in organic drugs or preparations containing gum, 
pectin, starch, sugar, albumin and various other constituents. 
Heat causes chemical changes in many organic compounds, 

431 



422 PHARMACY. 

such as alkaloids and glucosides, and may even entirely destroy 
sensitive constituents of organic drugs. Valuable volatile con- 
stituents are dissipated by exposure to heat. In the extraction 
of drugs with watery menstrua, by the aid of heat, starchy 
matter, which is wholly inert and therefore objectionable, may 
be dissolved out. Heat expels water of crystallization, causing 
certain salts to effloresce. Various other unfavorable effects are 
produced by temperatures not much above moderate heat. 
Higher temperatures are of course correspondingly destructive. 

1352. Fuel. — Substances of organic origin which are comparativelv 
readily ignited, burn rapidly and produce a large amount and high degree of 
heat, are used as fuel. These substances may be either solid, liquid or gas- 
eous. Their principal constituent elements are C and H. To be available as 
fuel, they must of course be obtainable in sufficient quantities at moderate 
cost. 

The products of the combustion (667) of fuel must be gaseous, little, if 
any, solid residue remaining. 

I 353« The amount of heat produced by the combustion of any particular 
kind of fuel is constant without reference to the method of combustion (or oxi- 
dation)— whether the fuel be burnt with oxygen, air, or a metallic oxide. 

1354. The intensity of heat, or the temperature (314) produced by the 
combustion of any given kind of fuel, depends upon the rapidity with which 
the fuel is oxidized. 

I 355- Among the solid fuels are wood, charcoal, anthracite, coke, and 
soft coal. 

Among the liquid fuels are coal oil and its products (particularly gaso- 
line), fixed oils and alcohol. 

Among gaseous fuels are the gaseous hydro carbons, of which the com- 
mon coal gas is most familiar; "natural gas," which is also composed of 
hydrocarbons (mainly marsh gas), affords more intense heat than the artificial 
gas. Fuel gas, which is hydrogen mixed with carbon monoxide (produced by 
the decomposition of water by passing steam over coal heated to an tntense 
temperature) (676), is even better than natural gas; and hydrogen, as already 
stated elsewhere (670), produces in its decomposition the highest temperature 
obtainable. 






PHARMACY. 



423 



1356. The quantity of heat obtainable from the perfect combustion of 
any particular kind of fuel is expressed in " heat units " or thermal units (335). 

The following table gives the heat units obtainable from the most import- 
ant fuels: 



Hydrogen. 
Carbon.. . . 



Marsh gas 

Olefiant gas 

Crude petroleum. . 

Wax 

Tallow .. 

Alcohol 

Carbon monoxide. 



Burnt to water 

" to carbon dioxide. .. . 
" carbon monoxide. . . 



to carbon dioxide 



and water 



" carbon dioxide, 



Heat Units. 



34 462 

8,080 

2,474 

I4-675 

11,849 

10,190 

10,496 

9,000 

7,i83 

2,403 



Water 
E7>aporatcd. 



62.66 

14 69 

4-50 

26.68 

21 55 
18 53 
19.04 
16.37 
13.06 
4-37 



It will be observed from the foregoing table that the greatest amount of 
heat is produced by fuels containing the greatest proportion of hydrogen; but 
the maximum amount of heat which might theoretically be obtained is never 
attained practically, because the combustion is never complete when solid fuel 
is used; seldom when liquid fuel is employed; and not always even when the 
fuel is gaseous. 

1357. The intensity of heat produced may be promoted by a full supply 
of oxygen or air, as by a good draft or the use of the bellows. The heat may 
also be intensified to some extent when solid fuel is used, by reducing the fuel 
to smaller pieces. Thus a pound of wood in the solid block and a pound of 
shavings of the same wood, produces the same amount of heat; but the shav- 
ings a more intense heat. 

For many operations a steady, well-sustained heat is neces- 
sary. Hard coal is the best fuel to this end. 

1358. Various kinds of heating apparatus employed for 
pharmaceutical purposes must of course depend upon two 
things — the kind of fuel employed and the uses to which the 
apparatus is to be put. It is not the purpose of this elementary- 
work to describe such apparatus. We will only mention that in 
chemical manufacturing establishments and in operating upon 
large quantities of material, open furnace fires are often used; 
stoves of various patterns are also extensively used for pharma- 
ceutical purposes; and that for most of the ordinary purposes of 
the pharmacist, gas stoves and burners are the most serviceable 



424 



PHARMACY. 



wherever gas can be had, whilst, where gas is not obtainable, 
gasoline stoves and burners, and spirit lamps are the best. 

1359. Steam heat, which is extensively employed in manufacturing 
establishments, is so effective because of the large amount of latent heat of 
steam and further, because of the fact that the temperature of steam does not 
exceed ioo° C. (212 F.), except when under pressure. The steam is applied 
either by means of coil submerged in the liquids to be heated, or by means 
of steam-jackets. By a steam-jacket is meant the space between the double 
shell of a kettle or pan, there being a larger shell rivited to the bottom of the 
vessel, so that steam can be introduced between the two shells. 

Hot water coil is also sometimes the best'means of keeping vessels and 
their contents warm in certain special operations, as, for instance: in coating 
pills, etc. 

1360. Among the gas burners, of which there is an almost 
infinite variety, some afford a large flame which may be applied 
to a considerable surface, and are, at the same time, furnished 
with supports for the vessels to be heated; while others give a 

narrow or pointed flame. Of the lat- 
ter kind the Bunsen burner is the most 
effective. It simply consists of two 
tubes, the larger of which is about 
four inches long and carries the mix- 
ture of gas and air which is ignited 
at the top of this tube, the gas being 
supplied near the foot of and inside 
the larger tube by a very small tube 
with a pin-hole orifice. An adjust- 
able valve is placed at the foot of and 
around the larger tube, but below 
the top of the small, narrow tube, 
and through this valve the air 
enters. If the amount of air supplied through this valve is 
sufficient for the complete combustion of the gas which issues 
into the tube, the flame produced at the top is bluish and affords 
intense heat, whereas if the valve is partly or entirely closed, so 
that the supply of air is insufficient, the flame will be yellow, 
smoky and luminous, and will not afford as high a temperature. 




Fig. 87. 



PHARMACY. 425 

The heat is most intense a little distance above the top of the 
tube or just below the middle of the flame. 

To prevent the dissipation of a part of the heat produced, 
jackets or chimneys may be placed over or around the burner. 

Sometimes two or more burners are combined for the pur- 
pose of producing a greater quantity of heat. 

Several varieties of gas burners are shown in figures 88 to 94. 




Bunsen burners. Figs. 88 to 94. 

1361. Coal-oil and gasoline stoves are of various sizes, from 
the kitchen range down to a small lamp are now manufactured, 
which are smokeless, nearly odorless, and afford very high tem- 
peratures. 

1362. The spirit lamp is by far the most cleanly and gen- 
erally useful small heating apparatus for the 'laboratory or 
the dispensing counter. It affords high temperatures without 
smoke, soot, or any disagreeable odor; and if the wick of the 
spirit lamp consist of loosely twisted cotton yarn, it can be 
spread so as to afford a flame of large diameter if desirable. 

1363. For the control and distribution of the heat, various 
devices are employed. One of these consists simply of wire 
gauze through which flame does not pass, so that when a gas 
burner is used the gas may be lighted either above or below 
the wire cloth, while at the same time the gas and its flame is 



426 



PHARMACY. 



spread over a greater surface. This wire gauze may at the 
same time serve for a support for flasks, beakers and other ves- 
sels. (See Fig. 95). 

1364. The sand-bath con- 
sists simply of an iron dish con- 
taining sand, and is also used 
for the purpose of distributing 
heat more evenly. It may be 
deep, so that flasks and retorts, 
when placed in it, may be 
entirely surrounded by the hot 
sand; or it may be shallow, so 
that flasks, beakers or dishes 
placed in the sand are heated 
only over the bottom and can 
at the same time be raised, the 
sand being allowed to run down 
under them for the purpose of 
immediately checking too great intensity of heat. 





Fig. 96 and 97. Water-baths in use. 
1365. The water-bath (Figs. 96 and 97) is a round vessel 
of copper or other suitable material in which water may be 



PHARMACY. 



427 



heated to any required temperature up to its boiling point. 
Vessels to be heated by means of the water-bath are placed on 
top and serve as covers. The water-bath should be only about 
two-thirds full, and the dishes placed over it should not fit so 
closely as not to permit the escape of the steam generated when 
the water is boiling. As the boiling-point of the water is con- 
stant, it follows that the dish and contents placed over the water- 
bath can not be heated any higher than just below that temper- 
ature. 

1366. Glycerin-baths, oil-baths and solution-baths are 
also useful, each affording high temperatures. 

The advantage in using these several kinds of baths, except 
the sand-bath, is not merely to distribute the heat, but also to 
limit its intensity. Thus, while the water-bath affords a temper- 
ature not exceeding 90° to 96 C, the glycerin and oil baths 
impart a heat not exceeding about 2oo°C, and the saturated 
solutions of salt afford various maximum temperatures, accord- 
ing to their character (394). 

1366. The following table of the effects of certain temper- 
atures will be found convenient for reference: 
Effects of Certain Temperatures. 



Freezing point of water 

Maximum density of water 

Standard temperature for sp.gr 

Common room temperature, about 

Fermentation active at about 

" Gentle heat," U. S. P 

Blood heat 

Boiling point of stronger ether 

Starch forms paste with water at about 

Albumen coagulates at about 

Boiling point of alcohol 

Water-bath heat, about 

Boiling point of water 

Oil-bath heat, about 

Glycerin-bath heat, about 



F. 



o.° 




+ 32. ° 


+4-° 




39- °2 








15. 




59 ° 


20.° to 22.° 


68 


to 71. °6 


25-° 




77-° 


32. ° to 38. ° 


qo 


to 100. ° 


37-° 




98.* 


37-° 




98 °6 


60. ° 




140. ° 


60. ° 




140.° 


78.° 




172 °4 


9 o.° 




194. ° 


100. ° 




212.° 


200. ° 




392° 


200. c 




392-° 



4-2S PHARMACY. 

Dry Processes Requiring Heat. 
1367- Desiccation means simply the drying of drugs and 
chemicals not involving their decomposition nor the loss of 
water of crystallization. 

1368. Fusion (376) is simply the liquefaction of solids by 
the aid of heat, which is frequently accomplished either for the 
purpose of inducing chemical reaction, as in the preparation of 
the iodides of arsenic and sulphur, or to render an intimate inter- 
mixture of several substances possible, as in making ointments, 
plasters, etc. 

1369. Exsiccation means the expulsion of water of crystal- 
lization (120 to 124) from crystallized salts by the aid of heat. 
Among the pharmacopceial preparations which are exsiccated or 
dried, are sulphate of iron. alum, carbonate of sodium, and 
others. 

I 37°- Ignition is a term used to designate the heating of any solid or 
mixture of solids to a very high temperature in contact with the air for the 
purpose of causing chemical changes, the product sought being a fixed 
residue. 

When the ignition includes rapid oxidation (1003) with the aid of some 
oxidizing agent (1006) as with a nitrate, but without explosion, the process is 
sometimes called deflagration. This is illustrated in the preparation of sodium 
arsenate (1005). 

The ignition is called incineratio7i when organic substances are burnt to 
ashes, the product sought being one or more of the constituents of the ash. 

When organic substances are strongly heated with a very limited supply 
of oxygen or air, so that a charred residue remains, consisting largely or 
entirely of carbon, the ignition is called carbonization. 

The term torrefaction has been used to designate the partial decomposi- 
tion of certain organic drugs by dry heat for the purpose of destroying some 
of their constituents without injuring others. Torrefied rhubarb retains the 
astringent effect, but does not have the cathartic properties of rhubarb. The 
author has never seen torrefied rhubarb, and is not aware that it is ever used. 

1371. Oxidation and reduction by means of dry heat have been 
referred to in Chapter LVIII of Part II. 

The term roasting is sometimes applied to the ignition of metallic sulphides 
and certain other inorganic compounds in free access of air for the purpose of 
causing their oxidation. Thus antimony sulphide may be roasted until both 
the antimony and the sulphur are oxidized, the sulphur forming the gas S0 2 , 



PHARMACY. 



429 



which passes into the air, and the antimony forming Sb 2 3 , which is the 
product sought. 

1372. The definition of the process of calcination as usually given would 
seem to include many different chemical decompositions by dry heat, includ- 
ing oxidation by roasting, the conversion of sulphate or oxalate of iron into 
ferric oxide, the incineration of bone to make bone ash, the conversion of 
sodium phosphate into pyro-phosphate, mercury nitrate to mercuric oxide, 
etc. The usual definition is: "the process of separating volatile substances 
from fixed inorganic matter by the application of heat without fusion." 
Others again say that it is "strongly heating inorganic crystalline substances 
with a view to the removal of water, C0 2 , or other volatile constituent." 

But the term calcination is derived from the word calx, which means lime, 
and has reference to the process by which lime-stone is converted into lime 
(777). The use of the term calcination should, therefore, be limited accord- 
ingly, and the true definition of 

Calcination is the conversion of metallic carbonates into 
metallic oxides by the influence of strong heat. 

The product is always the fixed residue, which is an oxide, 
while the bye-product is either C0 2 alone, or C0 2 and water. 

The most familiar examples of calcination are furnished by 
the preparation of lime, magnesia, and zinc oxide. 

*373- Destructive distillation or dry distillation is the 
decomposition of solid substances by heat, the solids being con- 
tained in retorts or cylinders connected with receivers in such a 
manner that the volatile products of the decomposition can be 
collected. Thus, in the manufacture of acetic acid, billets of 
oak wood are enclosed in large iron cylinders and there heated, 
air being excluded so that the wood, instead of undergoing com- 
bustion, is decomposed by the high temperature with the for- 
mation of acetic acid besides very many other products. The 
acetic acid thus produced vaporizes, distills over, and is col- 
lected in the receiver as pyroligneous acid, which is simply 
impure acetic acid. 

1374. Sublimation (377 and 406) as a pharmaceutical proc- 
ess is the vaporization of solids by heat under such conditions 
that the vapor is collected and condensed back to the solid state. 
The object of sublimation is to separate volatile from fixed sub- 



43° PHARMACY. 

stances, and it may either be one of the steps in the process of 
production of a volatile solid, as in the preparation of calomel 
and corrosive sublimate (794), and in the separation of benzoic 
acid from benzoin, in which that acid is contained naturally; or 
the sublimation may be a method of freeing a volatile substance 
from fixed impurities, as in the resublimation of camphor and 
iodine. 



CHAPTER LXXVIL 

COMMINUTION. 



1375. The disintegration or comminution of solids is a 
necessary preparatory step in many pharmaceutical operations. 

For the preparation of mixed species (1536) most of the crude 
drugs which enter into them are required to be cut or crushed, 
and cut or crushed drugs are also frequently employed for mak- 
ing infusions, decoctions, solid extracts, certain tinctures, wines, 
vinegars an'd syrups, etc. 

Solids occurring in large masses or pieces, or in large crys- 
tals, must be reduced to smaller particles for purposes of extrac- 
tion or to hasten solution. 

1376. Among the various kinds of comminution or mechan- 
ical division are cutting, slicing, chopping, rasping, grating, con- 
tusion, grinding, trituration, levigation, elutriation, granulation, 
etc. Nearly all of these terms are self-explanatory. 

1377. For cutting, slicing and chopping plant drugs it 
is necessary to employ sharp edge-tools to avoid tearing or 
crushing and the consequent formation of powder. In many 
cases it is desirable to produce clean-cut, uniform pieces free 
from powder. Starchy roots and drugs of friable texture, as, 
for instance, althaea and rhubarb, when required for extraction 



PHARMACY. 431 

by maceration or digestion for the preparation of infusions or 
syrups, should not be cut with dull knives producing ragged 
fragments or shreds mixed with loosened starch granules, which 
render the product unclear. 

Pruning knives and shears, the ordinary tobacco cutter and 
good hash knives are, when well-sharpened, useful instruments 
for cutting-plant drugs. 

1373. Rasping and grating are applicable in a few cases, 
and are accomplished by means of large, coarse, half-round 
rasp and the ordinary graters used for culinary purposes. 

1379. Crushing and grinding, producing very coarse pow- 
der, is effected by means of iron hand-mills. These drug mills 
are constructed upon the same general principles as the large 
coffee mills of the grocery stores, and are capable of reducing a 
great variety of drugs to a moderate degree of disintegration. 
The drug to be passed through the iron drug-mill must first be 
broken or chopped if in pieces too large to pass between the 
grinding plates without difficulty, and it is frequently necessary 
to pass the same lot of drug through the mill several times in 
succession, setting the mill finer each time, before the powder is 
of the required degree of fineness. But fine powders can not be 
made by the use of the hand-mill alone (1382). 

1380. Drug mills driven by steam-power, such as Mead's disintegrator, 
grinding mills of iron, roller mills, burr mills, chasers, pot mills, etc., which 
are used only by drug millers and manufacturers, will not be described 
here. 

1381. The iron mortar and pestle are extremely useful to 
the pharmacist who desires to prepare his own powdered drugs 
as far as practicable, for percolation and for other purposes. 

The iron mortar, in order to be of great practical use, should 
be of at least six gallons' capacity. It must have a solid, heavy, 
iron pestle of perfect form and size to match the mortar (1384), 
and the grinding surfaces must be polished by powdering emery 

or sand until perfectly clean and lustrous. The top of the 



43 2 



PHARMACY. 




mortar should be flaring. It is much deeper than mortars 

intended for any other use, except 
that commonly employed for pre- 
paring mixture of almond. (Fig. 

9 8.) 

As the iron mortar is very 
heavy, and great force is expended 
in contusion (1383), it must stand 
firmly upon a block or pillar, rest- 
ing not upjon the floor but on the 
Fig. 98. ground. 

1382. With an iron mortar of from six to eight gallons capacit) it is not 
difficult to make quite five powders of nearly all kinds of drugs, if the quan- 
tity put into the mortar at one time be not greater than just enough to cover 
the bottom. When a plant drug is to be reduced to fine powder it is gener- 
ally best to run it through the iron mill first, and then to powder it in the 
iron mortar. 

%3%3- To break, bruise, crush or powder a substance in a 
mortar by means of blows with the pestle is called contusion. 

The directions in which the force is applied must depend upon the nature 
of the substance operated upon, but when pulverization is the object the blows 
must be accompanied by a grinding and sliding motion. 

1384. Any mortar must have a perfect, smooth, regular, 
spherically concave bottom. It must be of a sufficiently hard 
material of uniform and compact texture, neither porous, slip- 
pery, nor brittle. The convex surface of the head of the pestle 
should be of perfect form — neither flattened, 
pointed, nor irregular — and of a somewhat 
smaller radius than the curve of the grinding 
surface of the mortar, so that, while there can 
be but one point of contact, the divergence 
of the surrounding interval between mortar 
and pestle will be quite gradual. Fig. 99 
shows a proper relation between the grinding 
A small powder mortar. sur f aces of mortar and pestle. In mortars 
used specially for triturating (1385 and 1386) powders, the head 
of the pestle may be somewhat more flattened. 




Fig. 99. 



PHARMACY. 433 

1385. Trituration is the grinding produced in the mortar 
by a rotary motion of the pestle accompanied by pressure. 
The pestle is grasped firmly, the whole hand being used for the 
purpose. 

Small amounts of brittle solids can be reduced to fine powder by tritura- 
tion, and some substances which are not brittle can be powdered in the same 
manner, provided their disintegration is aided by the addition of a small quan- 
tity of some unobjectionable volatile solvent, as when camphor is powdered 
by trituration with the aid of a little alcohol or ether, or when lactucarium is 
powdered with the aid of chloroform, or iodoform with the addition of ether. 

Certain soft or tough solids may be powdered by trituration with hard 
substances, as when vanilla or fresh orange peel is rubbed to powder with 
sugar, or when abstracts and triturations are made with milk sugar. 

1386. Trituration is also employed for mixing powders, or 
to powder and mix substances at the same time. For these 
purposes the trituration is best performed by moving the pestle 
in circles, beginning near the center of the mortar, enlarging 
the circles toward the circumference, and returning toward the 
center again by gradually diminishing the diameter of the circles 
described. 

1387. When dry substances only, already in fine powder, 
are to be mixed by trituration, pressure is unnecessary, and when 
the substances triturated are liable to adhere to the mortar and 
pestle, as in the case with resins, gumresins, camphor, alkaloids, 
and several other kinds of dry solids, no pressure should be 
applied. 

1388. Mortars and pestles are also used for massing the 
ingredients in the prepara- 
tion of masses, troches, 
and pills, for preparing 
small quantities of solu- 
tions, making liquid mix- 
tures and emulsions, in the 
preparation of certain oint- Figs. lootoioa. Pill mortars, 
ments, cerates, and suppositories, and for many other purposes. 

Various kinds of mortars are employed. Shallow mortars of 
large diameter are the best for mixing powders and ointments; 




434 



PHARMACY. 




small, rather deep strong mortars are used for making pill 
masses; larger and still deeper lipped mortars for making liquid 

mixtures and emulsions, etc." 

Mortars and pestles 
are made of wedgevvood 
composition, porcelain, 
glass, and various other 
materials. Porcelain 

mortars are either glaz - 
ed or unglazed, each 
kind being useful for its 

Figs. 103 ana 104. Mixture mortar and pestle. Own Special purposes. 

Pill mortars of iron are not uncommon. 

Fig. 98 to 104 represent different kinds of mortars. 

1389. The spatula is as indispensable in pharmacy as the 
mortar and pestle. They are made of steel, platinum, silver 
and horn. Steel spatulas are the most useful because flexible 
and elastic; but the other materials are preferred in operating 
with substances which attack steel, as is the case with many 
chemicals. 

Spatulas are used not only to transfer substances from the 
shop bottle to the balance pan, or from one vessel to another, 
but to scrape off or scrape together substances adhering to 
mortar or pestle for the purpose of rendering possible the uni- 
formly intimate intermixture of the ingredients. 

In the preparation of some ointments, and even some com- 
pound powders, the spatula and slab may be preferable to the 
mortar and pestle. 

1390. Levigation is the trituration of substances to a fine state of divis- 
ion by means of a slab and muller, as paints are sometimes mixed, a liquid 
of some kind being added to the solid matter which is to be thus rubbed fine, 
so as to produce a soft paste. Water, alcohol and oil are used for this pur- 
pose. Sometimes the lexigation also involves purification, as when an insol- 
uble solid is triturated with water not only to reduce it to a finer powder but 
also to wash out any water-soluble impurities. 

1391. Elutriation is a process sometimes employed to separate fine 



PHARMACY. 435 

powder from coarse particles. It is applicable only to inorganic substances 
heavier than water and insoluble in that liquid. It consists in agitating the 
powder with a large volume of water, desisting while the coarser particles 
subside, and decanting into another vessel, the liquid holding the finer pow- 
der in suspension, after which this powder is allowed to deposit on the bottom 
and is then collected. 

Levigation usually precedes elutriation, and the substance which is to be 
thus powdered and sifted is subjected to these two processes alternately until 
the requisite amount of fine powder has been obtained. The product may 
be made extremely fine. Prepared chalk and purified antimony sulphide are 
elutriated. 

1392. The granulation of salts is effected by several different methods, 
which will be described later (1489). 

J 393* The powders produced by all of these several meth- 
ods are far from uniform. The greatest attainable uniformity 
of division is probably attained by trituration and by leviga- 
tion, whilst powders obtained by contusion and by grinding 
consist of particles of various sizes, some of them several times 
as large as others. 

To regulate this w r ant of uniformity as far as practicable the 
coarser particles are separated by means of sieves, the meshes of 
which are small enough not to admit of their passage through 
the sieve cloth with the finer particles. But this method can 
not, in the nature of things, produce a uniform degree of fine- 
ness in the powder obtained, for every particle of the drug can 
not be subjected to precisely the same treatment, and plant 
drugs are not of exactly the same texture throughout, so that 
the more friable tissues are not only powdered first but also 
reduced to a finer state of division than the tougher tissues. 
Thus a powder made to pass through a sieve of 40 meshes to 
the linear inch may consist of about equal proportions of mod- 
erately coarse, moderately fine, fine, and very fine powder. 

1394. This inequality of size of the particles of pow T der can 
not be remedied by sifting off the finest, as by passing the 
powder first through a sieve of 40 meshes to the inch and then 
through another of 50 meshes to the inch, for the obvious reason 
that it is altogether impracticable to reject the bulk of the drug, 



436 PHARMACY. 

and also for the still more potent reason that it frequently hap- 
pens that the finer powder consists of the most active portions 
of the drug, the tougher portions, which are last reduced to 
powder and form coarser particles, containing a greater propor- 
tion of woody fibre or other inert matter. 

1395. From what has been stated in the preceding para- 
graph it will be readily understood that whenever a drug is 
powdered two conditions must be fulfilled in order to obtain a 
proper product, viz.: 1. The entire quantity put in the mill or 
mortar must be reduced to powder, and 2, the powder obtained 
must be well mixed before any portion of the product is taken 
away. 

1396. Comparatively coarse powders are employed for mak- 
ing extracts, such as infusions, tinctures, fluid extracts, solid 
extracts, abstracts, etc., while very fine powders are necessary 
for the preparation of compound powders, pills, troches, etc. 
Powders administered as such, or entering into medicines as 
such, can not be too fine. 

1397. The relative fineness of powders is indicated in 
the Pharmacopoeia by means of numbers referring to the meshes 
in the sieve cloth. Thus a powder which passes through a 
sieve cloth having 80 meshes to each linear inch is called a 
No. 80 powder ; one that passes through a sieve cloth of 40 
meshes to the linear inch is a No. 40 powder, etc. 

No. 80 powder is called "very fine"; No. 60 powder is 
referred to as "fine"; No. 50 is ''moderately fine"; No. 40 
"moderately coarse"; and No. 20 is "coarse" powder. 

1398. The sieves used by pharmacists for ordinary pow- 
ders are usually made of brass wire cloth if coarse, or of silk if 
fine. The sieve frames are generally circular. Sometimes they 
are provided with covers above and beneath to prevent the dust 
from rising, and they are then called " drum sieves." 

1399. Dusted powders are produced by chaser mills, and are so called 
because they are so fine as to rise like dust with the currents of air created by 
the revolutions of the mill stones, and are deposited on the floor outside of 
the tall iron cylinder surrounding the stones, or on shelves in the mill box. 



PHARMACY. 437 

1400. Very friable masses, such as magnesium carbonate and bismuth 
subnitrate, are powdered by simply rubbing them gently against the cloth in 
a- sieve. 

1401. Colored substances become lighter in color when powdered, and 
their color grows lighter as the powder gets finer. 



CHAPTER LXXVIII. 

SOLUTION IN PHARMACY. 



1402. In Part I, Chap. X, a brief account was given of the nature of 
solution, the difference between simple and chemical solution, the miscibility 
of liquids, solvents and solubility, etc. The student should here refer again 
to that chapter. 

1403. To dissolve solids most expeditiously they are first 
crushed or powdered, so that the surface exposed to the action of 
the solvent may be increased. 

Another effective means of facilitating solution is agitation. 
Stirring or shaking the solvent together with the substance 
which is to be dissolved insures more rapid solution because it 
brings each portion of the one in contact with fresh portions of 
the other. If a solid substance resting on the bottom of a vessel 
be covered with a sufficient amount of the proper solvent, and 
the solution allowed to proceed at perfect rest, the solid would 
soon be enveloped in or covered up by the solution first formed 
at the surface of contact, and this solution, interposing between 
the solid and the remaining portion of the liquid, would retard 
the process, but agitation would at once distribute the dissolved 
matter throughout the whole body of liquid. 

1404. To bring the solid in contact with new portions of 
solvent successively the solid may be placed in a perforated dish 
or basket, or in a loose bag, or on a colander or perforated 
diaphragm, just below the surface of the solvent, so that the 
solution may descend to the bottom of the vessel as fast as it is 



438 PHARMACY. 

formed, other portions of liquid at once occupying its place in 
contact with the solid. This is called circulatory displace- 
ment. 

1405. That the application of heat generally hastens the 
solution of solids will be easily understood from the fact that 
the solid must take up latent heat (311) in order to become 
liquefied (385). 

A warm or hot solvent generally dissolves a larger quantity 
of solid matter, and dissolves it more rapidly than a cold 
solvent. 

Thus 200 ounces of boiling- water will hold 100 ounces of potassium 
chlorate in solution; but when this solution is allowed to cool to the ordinary 
room temperature, only about 12 ounces of the salt will remain in the liquid, 
88 ounces having crystallized out as the temperature gradually decreased. 

1406. But heat does not invariably aid the solution of 
solids, for common salt (sodium chloride) does not dissolve 
better in hot water than in cold, and the same is true of calcium 
hydrate, acacia, and a limited number of other water-soluble 
solids. Nor is the difference between the solubility of a solid 
in a hot solvent and its solubility in the same solvent at a lower 
temperature generally as great as in the case of potassium 
chlorate in water as described in the foregoing lines. 

1407. Maximum solubility. — Experimental results with numerous bod- 
ies would seem to indicate that each substance is soluble in the greatest pro- 
portion in any given solvent at some fixed temperature being soluble in less 
amount either above or below that temperature. A most striking example is 
furnished by sodium sulphate, which reaches its maximum solubility at i5. c 6C. 
(6o r F.), the solubility decreasing on either side of that point so that at 
ioo c C. (212 F.) the solubility is nearly the same as at o. c C. (32 F.) 

1408. A solution of one substance may be an effective solv- 
ent for another substance (188). Thus, aloes is entirely soluble 
in four times its weight of boiling water, because some of the 
constituents of the aloes which are insoluble in pure water are 
nevertheless soluble in a strong water solution of the other con- 
stituents of the drug; but this strong solution of the whole of 
the aloes in four times its weight of boiling water can not be 
diluted by the addition of more water, hot or cold, without 



PHARMACY. 439 

becoming turbid, and if a sufficient quantity of water be added 
the greater part of the dissolved matter will separate. 

1409. Compound solution is a term often employed. It 
is synonymous with the expression chemical solution (190). At 
the same time the title compound solution is also used to designate 
pharmaceutical solutions containing more than one ingredient 
aside from the solvent, as for instance the ''compound solution 
of iodine" containing iodine and potassium iodide. 

1410. In paragraph 188 a definition was given of a sat- 
urated solution. We will now add that a solution of a solid, 
saturated at a given temperature, is not saturated at a higher 
temperature, and a solution of gas saturated at a given tempera- 
ture is no longer saturated when the temperature is lowered. 

141 1. But we may have a super-saturated solution in 
many cases, when the solution of a solid is made saturated at 
any temperature and then slowly cooled a few degrees lower, 
no separation resulting. The solution thus formed may contain 
or retain a larger quantity of dissolved matter than it would 
have been possible to dissolve in the solvent except at a higher 
temperature than the solution now has. 

A super-saturated solution of sodium sulphate may be made which will 
remain free from deposited salt for an indefinite period if kept at abso- 
lute rest, but which contains so large an amount of the salt in solution that 
when it is suddenly agitated, or when a crystal is dropped into it, the entire 
solution solidifies into a crystalline salt mass. But tnis is an exceptional 
case. 

1412. Partial solution is of very frequent occurrence in 
pharmaceutical operations. 

Mixtures of solid substances, or drugs of a heterogeneous 
structure or composition, such as the plant drugs, are generally 
only partially soluble in any one solvent. Thus a gum-resin 
yields its resin to alcohol but not its gum, whereas it yields to 
water its gum but not its resin. Roots, barks, leaves and other 
plant parts yield different substances to different solvents, so 
that both the composition and the amount of the extract 
obtained differ according to the menstruum employed. 



44° PHARMACY. 

1413. When mixtures of soluble and insoluble inorganic substances are 
separated from each other by the solution of the soluble contents, this process 
is called lixiviation. The most familiar illustration of lixiviation is the extrac- 
tion of the potassium carbonate from wood ashes by treating the ashes with 
water. 

1414. Fractional solution. — The application of different solvents, one 
after the other, for the purpose of separating substances of different solu- 
bilities, is sometimes called fractional solution. The two or more solvents 
used may differ only in temperature, or in strength. 

1415. To facilitate the solution of gases in water, cold and pressure are 
applied. 

Cold water dissolves more chlorine than warm water; to charge " carbonic 
acid water" with as large a quantity of the gas C0 2 as practicable, the water 
must be chilled and the gas must be forced into a strong " fountain " where it 
is agitated with the water, the amount of gas dissolved being in direct ratio to 
the pressure imposed. When the pressure is removed by opening the " fount- 
ain," C0 2 rushes out of the solution. If the carbonic acid water be heated all 
of the " carbonic acid gas " will be expelled. 

1416. The solution of liquids in other liquids is a common phenom- 
enon. Many liquids are miscible with each other. A mixture of glycerin 
and water is as truly a solution as the not more homogeneous liquid obtained 
by dissolving sugar in water. 

Again, some liquids are soluble in their proper solvents only to a limited 
extent, as is the case with the volatile oils in reference to alcohol. 

Finally, we can dissolve a limited quantity of ether in water, and per 
contra a limited quantity of water in ether, and these two different solutions do 
not mix with each other. 

A saturated solution of carbolic acid in water is not miscible with a satu- 
rated solution of water in carbolic acid. 

1417. The most important solvents used in pharmaceutical 
operations are: water, alcohol, ether, chloroform, glycerin, 
volatile oils, carbon disulphide, fixed oils, and solutions of the 
acids and alkalies. 

1418. Water ao a Solvent. — Water is the most valuable of 
the simple solvents. Its solvent powers are great, it is itself 
entirely neutral, and it is universally present and easily obtain- 
able in a state of purity. 

1419. Water-soluble Substances. — Of the numerous sub- 
stances which are more or less soluble in water, many are neces- 
sary to the existence of plants and animals, and others are of 
the utmost importance in the arts and manufactures. 



PHARMACY. 441 

Among the water-soluble organic substances are: Sugar, gum, 
the normal albuminoids, and many organic acids. In addition 
to these groups, an infinite variety of complex organic bodies, 
as the tannins, a great number of glucosides and other neutral 
principles, and most of the alkaloidal salts, are also water- 
soluble. 

Among the water-soluble inorganic substances are: the alkalies, 
the stronger acids, and most of the salts. Thus the compounds 
of potassium and sodium are with but few exceptions readily 
soluble in water; the nitrates are soluble, except the normal 
nitrates of mercury and bismuth, which are decomposed by 
water, and the basic nitrates of the same metals which are insol- 
uble; the normal acetates are all soluble; the chlorides are sol- 
uble, except calomel and the chloride of silver; and many 
iodides, bromides, cyanides, sulphates, etc. 

1420. Substances insoluble in water. — Among the organic 
substances insoluble in water are: Cellulose, normal starch, coagu- 
lated albuminoids, resins and fixed oils; the volatile oils are 
sparingly soluble; and free alkaloids are generally very spar- 
ingly soluble. 

The morganic substances insoluble in water include all the 
solid, non-metallic elements, the metals, the oxides, sulphides, 
carbonates, phosphates and oleates of the heavy metals, and a 
number of other compounds. 

1421. Liquores. — The "liquores" or " solutions" of the 
Pharmacopoeias of the United States, Great Britain and Germany, 
are aqueous solutions of non-volatile substances, mostly inor- 
ganic chemicals. 

1422. Alcohol as a Solvent. — Alcohol ranks next to water 
as a simple solvent. It is indispensable in the arts and manu- 
factures. Instead of being absolutely inactive, however, as water 
is, alcohol, when introduced into the body of man or animal, 
produces marked effects which greatly limit its usefulness. 



442 PHARMACY. 

1423. Alcohol-soluble Substances. — Alcohol dissolves 
resins, volatile oils, most of the free alkaloids, and many of the 
neutral proximate principles of plants. 

It also dissolves the alkali-hydrates, some chlorides, iodine 
and a few other inorganic substances. 

1424. Substances insoluble in alcohol. — Cellulose, gums, 
starch and albuminoids are insoluble in alcohol. All the fixed 
oils are insoluble in that liquid, except castor oil and croton oil. 
Alkaloidal salts are generally far less soluble in alcohol than in 
water. 

Inorganic salts are mostly insoluble in alcohol. 

1425. Ether as a Solvent. — Ether is an effective solvent 
for fixed oils and fats, which, as has already been stated, are 
insoluble in water, alcohol and glycerin. Ether also dissolves 
certain resins, volatile oils, alkaloids, and various other organic 
compounds. Inorganic substances are generally insoluble in 
ether, as are also cellulose, starch, gum, sugar, and albu- 
minoids. 

1426. Chloroform dissolves a great number of the alka- 
loids, and is also an effective solvent of fats and fixed oils, resins, 
and many other substances. 

1427. Glycerin as a Solvent. — Glycerin dissolves a great 
variety of substances, both organic and inorganic. It is a 
specially effective solvent for tannin and organic tannin com- 
pounds. 

1428. Menstrua. — A liquid used chiefly as a solvent, but 
also in part as a vehicle for medicinal substances is called a 
menstruum. The most common pharmaceutical menstrua are ; 
water, alcohol and syrup. 

1429. Among the pharmaceutical solutions are: the liquores, 
waters, mucilages, syrups, infusions, decoctions, spirits, tinc- 
tures, fluid extracts, wines and vinegars. 



PHARMACY. 



443 



1430. Solutions are made in mortars, dishes, beakers, flasks, 
and various other vessels. When solids in a state of powder, 




Figs. 105 to 107. Nests of beakers. 

coarse or fine, are to be dissolved, beakers and flasks are prob- 
ably the most convenient vessels for the purpose, especially the 
beakers (Figs. 105 to 107). 



CHAPTER LXXIX. 

FILTRATION AND OTHER METHODS OF CLARIFYING LIQUIDS. 

1431. When solutions of solids are prepared it often happens 
that the product is unclear from the presence of particles of 
dust and other insoluble solids. Many liquid extracts, as infu- 
sions, tinctures, etc., and other liquids, may be turbid from 
suspended particles of solid matter. To separate these solid 
particles so as to render the liquid perfectly clear, the latter is 
passed through some porous filtering medium, such as unsized 
porous paper, or paper pulp, or glass wool, asbestos, powdered 
glass, magnesium carbonate, calcium phosphate, charcoal, etc. 
This process is called filtration, and the clear liquid thus 
obtained by it is called a filtrate, and the paper or other medium 
through which the filtration is effected is called a filter. 



444 PHARMACY. 

1432. Filter paper is the most convenient and effective 
filtering medium for almost all liquids not too viscous to be 
filtered. 

There are several grades of filter paper, differing in color, purity, thick- 
ness, and porosity. 

Gray filter paper is sufficiently free from iron to be useful for the filtration 
of many pharmaceutical liquids, as tinctures, waters, and oils, but not suitable 
for the filtration of solutions of chemicals, such as acids, alkalies, and salts. 

White filter paper 'is always purer and sometimes absolutely free from 
iron and other impurities liable to be found in the gray paper. Chemical 
filter paper is manufactured at Grycksbo, in Sweden, which is in every way all 
that can be desired, leaving the least possible amount of ash when burnt. 
Solutions of chemicals, unless so corrosive as to attack the paper itself, can be 
freely filtered through good white filter paper without discoloration or con- 
tamination of the filtrate. 

But for pharmaceutical purposes, coarse, thick, very porous, white filter 
paper, which can be safely used for all non-corrosive liquids, and which will 
at the same time admit of rather rapid filtration, is the best kind. 

It may be had either in whole square sheets, or cut into round filters of 
various sizes ready for use. The latter kind is the most convenient, and at 
the same time the most economical, as its use involves no waste. 

x 433- Paper filters are either plain or plaited. 

A plain or simple filter is made by first folding the round 
paper across the center once, and then folding the double half- 
circle thus formed, also in the center, this second fold being 
opened out again; then one flap or end of the half-circle is 
folded in the middle so that its edge coincides with the crease 
which divides the half-circle in two equal parts, and the other 
end or flap is folded on the opposite dde also with its edge against 
the center crease. The paper as now folded is a quarter seg- 
ment of the circle. The filter is now opened out, and will be 
found to be of three thicknesses of paper on two opposite sides, 
but of only one thickness of paper on the two other opposite 
sides, while the perfect cone formed by the open filter fits per- 
fectly in a funnel of 6o° angle. 

Plain filters are used for collecting and washing precipi- 
tates, and often also for simple filtrations; bat the filtration of 
large quantities of liquids through plain filters is too slow, 



PHARMACY. 445; 

because this filter, when properly fitted into the funnel, lies close 




Figs. 108 to no. Making a plaited filter. 
to its sides all around so that the liquid can not pass through the 
paper except at the apex. 

Plaited filters are made as shown in Figs. 108 to 113, and are 
preferred to the plain filter when rapid filtration is desirable, as 




Figs, in to 113. Plaited filters, 
the plaited filter leaves a number of chan- 
nels between the paper and the funnel, per- 
mitting the liquid to run off more freely. 

1434. Glass funnels fit for all pur- 
poses must have an angle of 60 degrees. 
Such funnels are the only kind in which a 
plain filter can be fitted snugly, and, there- 
fore, no other funnels can be used for col- 
lecting and washing precipitates, while 
they are as good as any other funnels for 



446 



PHARMACY. 



all other purposes. Funnels of other angles can be used for 
filtration with plaited filters. (See Figs. 118 and 119.) 

A perfect funnel should also have a regular and well formed 
throat, and its stem should have a beveled end so that the liquid 
passing out of it will form one undivided stream. (See Figs. 
114, 115 and 116). 





H35- 



Figs. 115 to 119. Funnels and filter stand. 

The paper filter and funnel must fit each other; the 
upper edge of the filter should be about 
% to }4 inch below the top of the funnel. 

1436. Filter stands are shown in 
Figs. 116 and 120. The stand repre- 
sented in Fig. 120 is also a lamp stand, 
but is commonly, although very improp- 
erly, called a u retort stand." 

In filtration the funnel must be so 
placed that its stem is within the top 
of the vessel in which the filtrate is 
collected, and the end of the stem should 
touch one side of the receiving vessel 
so that the stream of liquid may run 
down that side to avoid spattering. 

Fig. 120 also shows an inverted flask 
placed over the funnel to furnish a con- 
tinuous flow of the liquid to be filtered, 
and the receiving vessel is a beaker. 




Fig. 120. Lamp stand 
and continuous filtration 



PHARMACY 



447 



1437. Ribbed funnels are sometimes used to render plaited 
filters unnecessary. 

Filter- baskets are also employed for the same purpose — to 
provide a passage for the liquid between the filter and the fun- 
nel. The filter basket is a funnel-shaped frame of wood, whale- 
bone, or wire; it is placed in the funnel, and the filter in the 
basket. 

Or glass rods, little strips of wood, etc., may be placed 
between the filter and the funnel. 

1438. Viscous liquids do not easily pass through filter paper, 
and some thick liquids can not be filtered at all. But many 
viscous liquids which pass through the filter only with great 
difficulty when of the ordinary temperature can be readily fil- 
tered if warmed sufficiently. 

Corrosive liquids must be filtered through glass, wool, coarsely 
powdered glass, asbestos, or sand, instead of paper. 

I 439- Colation or straining is the separation of solid par- 
ticles from liquids by means of flannel, muslin, felt and other 
fabrics, cotton, tow, sponge, etc. It differs from filtration only in 
regard to the filtering media used, which do not always produce 




Figs. 121 to 123. Colation; straining cloths and frames. 

as perfect results as filtration through paper. The liquid which 
passes through the strainer is called the colature. A colature 
is rarely as clear as a filtrate, and the clarification begun by eola- 
tion is often finished by filtration. 



PHARMACY. 



A tenaculum is a square wooden frame for supporting strain- 
ing cloths. Several such frames are shown in Figs. 121 to 125. 




Figs. 124 and 125. Colation. 

A Hippocrates* sleeve is a pointed straining bag. Such bags 
are made of cotton cloth or of flannel. 

1440. Decantation. — In many cases the most convenient 
and effective method of clarifying liquids, especially when large 
quantities are operated upon, is to allow the liquid to stand at 
perfect rest a sufficient time to insure the subsidence of all the 
particles of solid matter which are suspended in it and make it 
unclear, and then to remove the supernatant clear liquid by 
decantation. Decantation is the process of carefully pouring off 
a liquid from a precipitate, a sediment, a mass of crystals, or 
any other substances from which it is desired to separate that 
liquid perfectly. 





<u a \ iimis;.™:;;; .,,;},;-■,-; ,~,~, ,„„;.„„. ;;;;",:,;:::':! , : ii !3i'~L : .r:-- : — " 

Figs. 126 and 127. Decantation, with and without uie guiding rod. 



PHARMACY. 



449 



To pour a liquid from one vessel to another without spilling 
is an art which every pharmacist must acquire. When the ves- 
sel containing the liquid is provided with a flaring top or with 
a lip and is not quite full, it is easy enough ; but otherwise it 




Figs. 128 and 129. Siphons of glass tubing. 

is a feat which requires practice before it can be safely and well 
done. The use of the guiding rod helps; or the rim of the con- 
tainer may be greased. 

Instead of decanting the liquid, 
the siphon may be used with 
great advantage. 

1441. Pharmaceutical liquids, 
which it is possible to render as 
clear as the most transparent 
crystal, should never be in any 
other condition. Even the fixed 
oils and syrups of a drug- store 

J ^ "■ VJ1 u 5 -31-uic Fjg. 130. Rubber siphon. 

should be filtered through paper as far as their nature permits. 




450 PHARMACY. 

1442. There are several other methods of clarifying certain 
turbid or unclear liquids which will not pass through filter 
paper, or which can not be rendered clear by filtration, eolation 
or subsidence and decantation. 

Sometimes the application of heat is sufficient to cause the 
impurities to rise to the surface so that they can be skimmed 
off, or the diminished density of the liquid resulting from the 
increased temperature may render the subsidence of suspended 
solid matter possible. 

When the unclearness of the liquid is due to tannin, the 
addition of a little gelatin precipitates the tannin and clarifies 
the liquid. 

Albumen added to an unclear liquid frequently clarifies it on 
the application of heat sufficient to coagulate the albumen 
which then carries the suspended solid matter down with it. 
The white of one egg is usually sufficient for a gallon of liquid, 
and all the egg albumen added is of course removed again by 
the coagulation. 

When the unclearness depends upon tffe presence of pectin 
or of albumin, and the liquid at the same ::me contains sugar, 
the clarification may be effected by fermentation; or, if the cloud- 
iness is due to albumin alone, the liquid may clear up when 
heated to the temperature at which albumin coagulates. 

1443. Insoluble solid matter which is held in suspension in 
a liquid, and which gradually descends to the bottom of the 
vessel in vhich the liquid is contained, constitutes, after its sub- 
sidence, what is called sediment. 

1444. Decolorization ar.d deodorization ::' crganic sub- 
stances in the liquid state is accomplished by filtration through 
charcoal. Sometimes vegetable charcoal is sufficient for this 
purpose, but animal charcoal is far more effective. Charcoal 
has the property of absorbing many coloring matters and 
odorous substances. 



PHARMACY. 



45 



CHAPTER LXXX. 

EVAPORATION, DISTILLATION, AND THE GENERATION AND SOLUTION 

OF GASES. 

1445. In Chapter XX of Part I you read about the relation 
of heat to the three states of aggregation of matter, the lique- 
faction of solids by heat, and the vaporization of both solids 
and liquids. Now refer to that chapter again and refresh your 
memory concerning fusion and ?nelting points, fusible and refractory 
bodies, volatile and fixed bodies, the tension of vapors (7 7 and 279), 
evaporation, vaporization, ebullition, boiling points ', distillation and sub- 
limation (1374). 

1446. Spontaneous evaporation is the slow conversion of 
volatile substances into vapor at ordinary temperatures. 

Evaporation is the comparatively rapid conversion of vola- 
tile bodies into vapor at temperatures below their respective 
boiling points. 

Vaporization is the rapid conversion of substances into 
vapor at their respective boiling points. 

1447. Boiling or ebullition is the bubbling agitation caused 
in liquids by their active vaporiz- 
ation at the temperature beyond 
which the liquid can not exist 
under the ordinary pressure, i. e., 
its boiling point. But it is fre- 
quently necessary or desirable to 
heat liquids at or near the boil- 
ing point for other purposes than 
to vaporize them, as: to aid solu- 
tion, to promote chemical reac- 
tions, to destroy certain objec- 
tionable constituents, etc. 

For this purpose boiling vessels 
are employed, such as flasks. 
deep dishes, etc. 




45 2 



PHARMACY. 



1448. Evaporating dishes, on the contrary, are shallow, 
because the exposure of an extended surface of the liquid is one 




Figs. 132 to 135. Porcelain evaporating dishes. 

of the necessary conditions of rapid evaporation. Figs. 132 to 
135 represent small porcelain evaporating dishes, such as are 
most useful to pharmacists. 

To promote evaporation we may: 1, use shallow vessels; 
2, apply heat; 3, stir the liquid so as to facilitate the escape of 
the vapor from the interior of the liquid; 4, constantly change 
the air above the evaporating liquid, replacing the saturated air 
by drier air, which is accomplished by creating currents in the 
act of stirring the liquid or otherwise, or by arranging so that 
there is a draft or continuous change of air in the whole room 
where the evaporation is going on; 5, so arrange that as large a 
portion of the outer surface of the evaporating dish is exposed 
to the heat as practicable; and 6, by lessening the pressure 
superimposed upon the evaporating liquid. 

1449. Evaporating dishes are made of porcelain, glass, 
copper, silver, tin, enameled iron, " agate ware" or "granite 
ware," etc. 

1450. Evaporation is carried 1, to dryness; 2, to a given 
volume; 3, to a given weight; 4, to a given specific weight; 5, to 
a certain consistence; 6, to crystallization; 7, to granulation; 
8, to the complete expulsion of some objectionable volatile con- 
stituent; 9, until there is no further loss of weight; etc. 

1451. In conducting an evaporation it is necessary to know 
what temperature the substance will bear which is exposed to 
heat. Very many medicinal substances are so sensitive to heat 
that extreme care is necessary to avoid injuring them. The 



PHARMACY. 453 

water-bath is often used. A higher temperature than that 
afforded by the water-bath must not be used in the evaporation 
of solutions of organic substances. 

1452. The vacuum pan is an apparatus in which a covered 
evaporating vessel is combined with an air pump and a con- 
denser in such a manner that the atmospheric pressure is 
removed or lessened, whereby the evaporation is made to pro- 
ceed rapidly at a lower temperature, while at the same time the 
contents of the evaporating pan is not exposed to contact with 
the air. 

1453. Distillation is the vaporization of liquids in an appa- 
ratus so constructed that the va^or formed in one vessel is con- 
ducted into another vessel in which it is condensed back to the 
liquid state so that it can be recovered. The product is always 
liquid and is called the distillate. 

1454. There are many different kinds of distilling appara- 
tus. The most common are: stills, flasks and retorts. 

I 455- Stills are made of copper, tin, lead, iron, earthen 
ware, and other materials. The best stills are the simplest in 
form, which can be easily taken apart, cleaned, and put together 
again. The body of the still should have a sufficiently large 
opening at the top to render it easy to get at ever)'- portion of 
the interior in cleaning it. The head should also be of equally 
simple construction and should fit the top of the body perfectly. 
The general shape of a still, when the head is joined to the body, 
is like that of the retort shown in Fig. 136. If a horizontal line 
be drawn across the retort just below the tubulure in which the 
thermometer is inserted, the upper part, which is bent toward 
the left and then on a downward incline until it is inserted in 
the condenser, would represent the head of the still, while the 
body of the retort resting on the wire cloth over the flame of the 
gas burner represents the body of the still. 

1456. Fig. 136 also shows a lamp stand supporting both the 
gas burner and the retort, a Liebig's condenser on the stand, and 



454 



PHARMACY. 



a water vessel supplying cold water to the condenser, while a 
beaker placed on the table receives the warm water running out 




Fig - . 136. Distillation. 

of the condenser, and the whole apparatus is represented as in 
use in the separation of alcohol and water from each other by 
distillation (" fractional distillation "). Two flasks have already 
been filled with "distillate," and a third is now being used as a 
"receiver," while several empty flasks are on the table ready for 
use. 

1457. Retorts are generally made of glass; sometimes of 
earthen ware. It is practically a flask with a long neck bent at 
an angle of about eighty degrees to the body. It should have 
one or two tubulures or necks with ground glass stoppers. 

1458. Flasks are shown in Figs. 97, 131, 136, 138 and 139. 
Flat bottomed flasks are most convenient, but pear-shaped 
flasks are also useful. The neck of a distilling flask should be 
of large diameter, but not long. A wide neck is necessary 
to permit the insertion of perforated rubber stoppers or corks 
through which glass tubes, the thermometer, and other acces- 






PHARMACY. 



455 






sories can be introduced. A glass tube extending only a short 
distance below the stopper and bent at a right angle about an 
inch above, serves the same purpose as the neck of a still or 
retort, A safety tube, or " thistle tube," is used for charging 
the flask or to add liquids to its contents from time to time ; 
the upper thistle-shaped end serves as a funnel, and the lower 
end of the tube reaches nearly to the bottom of the flask. 

1459. Condensers are tubes or other conduits in which 
vapors are rondensed by abstracting from them their latent heat 
(401). The condensing space is usually surrounded by cold 
water which takes up that latent heat and becomes warmed by 
it ; as the temperature of the water rises it becomes necessary 
to renew the supply of cold water continuously. 

There are several different styles of condensers, of which we 
will mention only a few : the worm, Liebig's condenser, Mitsch- 
erlisch's condenser, the dome condenser, and the spiral glass tube 
condenser. 

1460. The worm consists of a 
spiral block tin pipe placed in a 
tub, barrel or tank, through which 
cold water flows. The block tin 
pipe is connected at the upper 
end with the neck of the still, while 
the lower end passes out through 
the side of the tub, barrel or tank, 
near its bottom. The receiver is 
placed under this exit tube through 
which the distillate runs out. 

1461. Liebig's Condenser 

consists of two tubes of different 

diameters, the smaller within the 

larger, fitted together by means of 

perforated stoppers or corks, or 

in some other convenient way. 

The inner tube protrudes at both 

ends, and the vapor is passed Fjg . I37 . Liebig's condenser. 

through it, while the outer tube carries the cold water. 




456 PHARMACY. 

1462. Mitscherlisch's condenser consists of a double cyl- 
inder, or of two tubes fitted together tightly at the ends and 
placed in a vessel of cold water. In this apparatus the con- 
densing space is not within the inner tube or cylinder (as in 
Liebig's), but between the two cylinders or tubes, so that the 
vapor forms a thin sheet in the form of a cylinder. The inner 
tube is open at both ends. Hence the thin sheet of vapor is 
placed between the cold water outside and inside the double 
cylinder. Tubes are, of course, provided through which the 
vapor passes into the condensing space at the top, and the con- 
densed liquid out of it at the lower end. 

1463. The dome-shaped condenser is a funnel-shaped 
still head with a gutter running along its lower edge inside. 
When this head is fitted upon the still, the gutter being a trifle 
lower at one side, the vapor is condensed against the cold inner 
sides of the dome, and the resulting liquid runs down along 
those sides into the gutter and out through an exit tube at the 
lowest point. The dome is surmounted by a small tank of 
which the dome is the bottom, and cold water is supplied to it 
to effect the condensation. 

1464. The upright small glass condensers, consisting of a 
spiral tube fitted into a larger tube shaped like a cylindrical per- 
colator, are very convenient and effective. 

1465. In all tube condensers the cold water is admitted at 
the bottom, and as it is warmed by the latent heat it absorbs 
from the vapor it rises to the top, where it is allowed to run off 
through a tube. 

1466. Receivers used in connection with retorts and flasks 
are usually made of glass. They are globe-shaped flasks with 
wide necks admitting of the insertion of perforated corks or 
stoppers when required. Sometimes these receivers are fitted 
to the retorts without the intervention of condensers, the 
receiver being in that case a condenser at the same time; it may 
be placed in cold water or broken ice, or a stream of cold water 
may be kept flowing upon it. 



PHARMACY. 457 

1467. For large operations metallic stills are the best; for 
smaller operations either retorts or flasks. But retorts are so 
awkward in form, and the complete distilling apparatus of 
which a retort constitutes a part is so rigid, that the inconvenience 
and liability to breakage greatly lessen their utility. Flasks, 
which can be fitted to the condenser by means of rubber 
joints, are generally preferred, and retorts are used only for 
special purposes. 

1468. Fractional distillation is the separation of liquids 
of different boiling points by distillation. When two or more 
liquids having different boiling points are mixed, and such a mix- 
ture is subjected to distillation, the most volatile liquid distills 
over before the others. Hence a separation of the several 
liquids by distillation is possible, the temperature being regu- 
lated accordingly. One of the constituents may be distilled 
over at one temperature, and another at a higher, temperature. 
In some such operations the boiling point may remain constant 
for some time, and then rise to a higher degree and again 
become stationary for a time. But complete separation by such 
means is rarely possible, and even approximate separation 
requires repeated distillations, because portions of the less 
volatile liquids are vaporized and carried along with the vapor 
of the more volatile. 

The distillation of mixtures of liquids for the purposes of 
separating them, collecting separately the portions distilling at 
different temperatures, is called fractional distillation. 

A common instance of fractional distillation is the separation 
of alcohol from water. (Fig. 136). 

1469. In many processes of distillation the vapor formed is 
the product of a chemical reaction taking place in the still, 
retort or flask. This may be called chemical distillation. The dis- 
tillation of water, or of alcohol, for purposes of purification, is a 
simple distillation, because the distillate is not a new substance 
formed by a chemical reaction during the process of distillation. 
But if you mix alcohol and sulphuric acid and distill that mix- 
ture your distillate will contain ether — formed by the action of 
the acid on the alcohol. 



458 



PHARMACY. 




1470. Closely resembling the processes of distillation is the 
generation of gases in flasks or other generators, with or with- 
out the aid of 
heat, the gases 
thus formed (by- 
chemical reac- 
tions) being 
passed through 
tubes into water 
or other liquids 
in which they 
are dissolved, 
being thus con- 
j| densed to the 
W liquid state by 

Fig. 138. Apparatus for the generation and solution of gases. 

Condensers are generally unnecessary in such cases, the sol- 
vent contained in the receiver being sufficient to absorb the 
latent heat of the gas, or the receiver being surrounded by (or 
placed in) cold water or broken ice. 

Sometimes the gas must be passed through water or other 
liquids to wash it before it is sufficiently pure to form a satisfac- 
tory product in the receiver. The receiver may be a flask, or a 
bottle, or any other convenient vessel, and in many cases it is 
necessary to disconnect it or remove it from time to time to 
shake the contents to facilitate the solution which is often car- 
ried almost or quite to the degree of complete saturation. 

The wash bottles are usually the so-called " Woulf's bottles,'* 
or bottles with two or three necks, so that they can be connected 
by tubing with generator and receiver, and, if necessary, admit 
of the insertion of safety tubes to relieve pressure in case of the 
stoppage of tubes, etc. 

Fig. 138 shows the generator (a flask) placed over a gas 
burner; a thistle tube is fitted to the neck of the flask, and the 
exit tube of glass connects by rubber tubing with two Woulf's 



PHARMACY. 



459 



bottles (the "wash bottles") and with an end bottle. Either the 
second Woulf's bottle or the end bottle may be the receiver; if 
the second Woulf's bottle is the receiver then the end bottle 
generally contains some solution which fixes the excess of gas 
absorbing it by chemical action so as to prevent its escape into 
the room. 





Fig. 139 and 140. Cutting glass tubing. 

To cut glass tubing at any desired point, make a transverse indentation 
on one side by a few strokes with the edge of a three-cornered file, and then 
break the tube at that point, holding the tube as shown in Fig. 140, the thumb 
nails being under the tube and opposite the file mark, which should be held 
upward. 

1471 . Flasks, Woulf's bottles, receivers, and all other similar 
pieces of apparatus required for chemical processes in the 




Fig. 141 to 143. Flasks and bottles with their fittings. 
preparation of pharmaceutical products, should be carefully 
cleaned and put away when not in use, the rubber stoppers and 



460 PHARMACY. 

tubing belonging to them being tied to their necks, and the 
mouths of the necks capped with paper to keep out dust, etc. 

When put together for use the glass tubes should be joined 
together with pieces of soft black rubber tubing. 

1472. Among the official products made by processes involv- 
ing distillation are: distilled water, alcohol, ether, chloroform, 
spirit of nitrous ether, etc., in the preparation of abstracts, oleo- 
resins, and certain fluid extracts, extracts, etc., the greater part 
of the menstruum is recovered by distillation. 

The methods of preparation of acids, chlorine water, the 
solutions of ammonia, etc., include " the generation and solution 
of gases." 



CHAPTER LXXXI. 

CRYSTALLIZATION AND PRECIPITATION. 

1473. Crystals, crystalline bodies, the formation of crys- 
tals, water of crystallization, and crystallography, were treated of 
in Chapters IV to VII, inclusive, Part I. These chapters should 
be reviewed here, and especially paragraphs 84, 100 to 105, 112, 
and 115 to 121. 

1474. Pharmaceutically, the process of crystallization con- 
templates the production of chemicals in the form of crystals. 
It serves three useful ends: 1, the separatio?i of crystallizable 
substances from amorphous (96) substances, or of two or more 
heteromorphous substances (95) when occurring together or 
when mixed; 2, purification (115 and 116); and 3, improveme?it of 
the appearance of the product. 

1475. The several methods of producing crystals, or of 
inducing matter to assume the crystalline form, were briefly 
mentioned in paragraph 119. But we will now add a few prac- 
tical considerations of special interest to the pharmaceutical 
chemist. 



PHARMACY. 46 r 

1476. By far the most common method of producing crys- 
tals is to induce their formation and growth in solutions. A 
crystallizable substance in a state of solution will separate from 
the solution in the form of crystals whenever the amount of 
solvent present is insufficient to retain the substance in solution. 
The ratio of solubility of a given solid in a given solvent is con- 
stant at any given temperature. A saturated solution of a 
crystallizable substance, therefore, deposits crystals whenever 
the amount of solvent is diminished by evaporation, or when 
the temperature of the solution is lowered (if the substance dis- 
solved is soluble in greater proportion at a higher temperature). 

There are accordingly two methods at once suggested by 
these considerations, by which we may cause the formation of 
crystals in solutions — evaporation, and the reduction of the tempera- 
ture of the solution. 

1477. The best crystallizers, or vessels in which to perform 
crystallization, are angular vessels with a rough interior sur- 
face. Perfectly smooth, spherical vessels, as dishes made of 
glass or glazed porcelain are not so good. For small quan- 
tities, however, glass and porcelain dishes are generally 
employed. 

1478. Points of attachment. — If angular or rough parti- 
cles, or sticks or strings, be introduced into solutions ready for 
crystallization, crystals will frequently begin to form at once 
upon their surfaces, and having been thus started the process 
goes on rapidly. 

Ex. — Rock candy is crystallized on strings; ferrous sulphate 
on strips of sheet lead; copper sulphate and ferrocyanide of 
potassium on sticks of wood; etc. 

1479. Nuclei. — In operating upon small or moderately large 
quantities, a convenient and effective method of promoting crys- 
tallization is to put into the salt solution a mass of crystals of 
the same salt. The crystals already formed will serve as nuclei 
for larger crystals, and to start the crystallization without delay. 

1480. Size of Crystals. — If large and well-defined crystals 
are desired, their formation must be very gradual. Slow 



462 



PHARMACY. 



cooling of the solution, or spontaneous evaporation of the sol- 
vent, and perfect rest, are the means to be employed. 





F igs. 144 and 145. The growing of perfect crystals of alum. 

When quickly formed, on the other hand, the crystals are 
small, and this will also be the result when the formation of the 
crystals is interfered with by agitation. Rapid cooling of the 
solution, or rapid vaporization of the solvent, and constant and 
brisk agitation are then required. 

1481. Larger crystals are generally formed in turbid 
than in clear solutions. Impure tartaric acid and citric acid 
yield larger crystals than the pure acids. This shows that the 
presence of foreign matters affect the process of crystallization, 
which is also shown by other observed facts. Even the form of 
crystals may be materially altered by the presence of other 
bodies; thus the regular cubic form of sodium chloride may be 
changed to the hemihedral form by the addition of small 
amounts of urea, glycerin, or crude tartar, or by placing a cubic 
crystal touched by fat or wax into the mother liquor. 

1482. A powdered crystallizable salt, immersed in a sat- 
urated solution of the same substance, gradually becomes coarse 
and distinctly crystalline, the larger particles of powder serving 
as nuclei for the crystals formed at the expense of the fine par- 
ticles which disappear. The salt in solution deposits upon some 
of the particles of powder, whilst a corresponding amount of the 
finer particles of powder enters solution. Fluctuations in the 
temperature hasten this change, for as the solution becomes 
warmer it is no longer saturated, and therefore dissolves some 
of the finest powder, and when it again becomes cooler the salt 



PHARMACY. • 463 

•which had dissolved at the higher temperature deposits upon 
the nuclei present, causing them to increase in size and distinct- 
ness of form. 

This is exemplified sometimes in mixtures containing a 
larger quantity of some water-soluble salt than the water pres- 
ent is capable of holding in solution at common temperatures. 
When, for instance, the physician's prescription calls for two 
drachms of potassium chlorate, to be dispensed in a mixture 
containing less than two fluid ounces of aqueous solvent, more 
than one-half of the salt will remain undissolved, and even if 
added in the form of extremely fine powder, it will after a short 
time become coarsely granular. 

1483. Nursing the crystals. — Crystals may be increased in 
size on the principle suggested in the preceding paragraph. 
The small crystals may be re-dissolved by gently warming the 
liquid in which they rest, and that is best effected -by setting the 
vessel in a somewhat warmer place for a little while. The 
remaining crystals will grow when the temperature is again 
slightly lowered. 

1484. Imperfect Development. — Crystals obtained from 
supersaturated solutions, or by fusion, are generally imperfect. 
Crystals resting upon the bottom or against the sides of the ves- 
sel, or against each other, can be but partially developed, and 
the result is usually a more or less confused mass of adhering 
or interlaced portions of crystals. Very rapid crystallization also 
produces imperfect crystals, as a rule. 

1485. Retarded Crystallization. — It often happens that 
without any obvious cause the deposition of crystals is delayed, 
no signs of crystallization being seen for many days, or even 
weeks, although the solution may be sufficiently concentrated, 
and that afterwards it may suddenly begin. Sometimes one or 
but few crystals of large size may be found formed where a 
large crop is expected. At other times again the formation of 
crystals begins early and yet proceeds extremely slowly. In 
exceptional cases the completion of the deposition of crystals 
may require several months. 



464 PHARMACY, 

i486. The character and solubility of the salt; the form* 
size and inner surface of the crystallizer; the quantity operated 
upon; the degree of temperature and concentration of the solu- 
tion; the constancy of the temperature of the air; and other 
conditions, may bear such relations to each other and to the 
crystallization as to cause unexpected rapidity or delay in h e 
process. 

1487. Water at perfect rest may be cooled to S or 10 degrees below the 
freezing point and still retain its liquid state; but a slight vibration imparted 
to the vessel will then cause sudden crystallization. 

1488. The liquid remaining after the deposition of crystals 
has ceased, or the liquid in which the crystals are formed, is 
called the mother-liquor. This liquor can be used to dissolve 
additional quantities of the same substance by the aid of heat, 
and the solution then cooled to produce crystals. When large 
quantities of the same salt are to be crystallized or granulated, 
it is convenient and economical to employ the mother-liquor 
instead of a fresh portion of solvent for each succeeding opera- 
tion. 

1489. Granulation of salts. — Soluble salts may be gran- 
ulated by rapid evaporation accompanied by agitation, or by 
rapidly cooling a hot saturated solution, stirring it constantly at 
the same time. The salt then separates in very small crystals. 
The crystals are small because they are rapidly formed, and 
because the agitation does not permit their growth. A salt in 
very 7 small crystals is said to be granular, or granulated. 

There is also another kind of granulated salts or products, of which 
" granulated citrate of magnesium " is an example. They are made by running 
a moist or dampened salt mass or mixture (it is usually moistened with alco- 
hol) through very coarse sieves, rejecting both the fine and the too coarse par- 
ticles, so as to produce a uniform size of granules which are nearty globular, 
but which, of course, do not have any crystalline structure. All that does 
not pass through a No. 20 sieve and all that does not pass through a No. 30 
sieve is rejected. 

1490. The crystals formed in solutions must be freed from 
adhering mother-liquor by draining them, or pressing them 
gently between cloth or bibulous paper, or by exposing them to 
a current of air until dry. 



PHARMACY 465 

1491. Crystals obtained by sublimation are small and free 
when the vapor is rapidly condensed at a temperature con- 
siderably below that at which the vapor was formed; but a 
cake is usually formed when the vapor is slowly condensed at a 
temperature but little below the heat required for the sublima- 
tion. 

1492. Precipitation as a pharmaceutical process has been 
discussed at considerable length in Chapter LX, because of the 
intimate relation it bears to certain chemical reactions. Para- 
graph 999 of a previous chapter states the law governing the 
formation of precipitates. 

1493. Precipitation is the formation of insoluble solids in 
liquids. Precipitation takes place in a liquid previously free 
from undissolved matters, and consists in the formation of 
solid particles insoluble in that liquid. 

Precipitation is the result of a change in the relation of the 
solvent to the matter it holds in solution. This altered relation 
may be brought about by a change in either the solvent, or the 
dissolved matter, or both. 

1494. Distinction should be made between intentional precipi- 
tation as performed in chemical or pharmaceutical processes, and 
the unintentional precipitations which are so often observed in 
pharmaceutical preparations, and which usually take place so 
slowly as to closely resemble the formation of sediment in 
turbid liquids. 

1495. Sediment. — Insoluble matter which deposits from a 
liquid, collecting at the bottom of the vessel, is not always a 
precipitate. Turbid liquids, holding insoluble matters in sus- 
pension, when allowed to remain at perfect rest a sufficient 
length of time, usually become clear by a slow separation of the 
solid matter which " settles" down at the bottom. This deposit 
is not a precipitate, but a sediment. When, however, the liquid 
is at first free from undissolved solid substances, but newly 
formed insoluble matters afterward separate from it in the 
solid state, this change is precipitation. 



466 PHARMACY. 

1496. Simple Precipitation is a precipitation unaccom- 
panied by any chemical reaction. It is most frequently the 
result of an alteration of the solvent, as when resin is precipitated 
from its alcoholic solution by diluting the solvent with water, or 
when a gum is precipitated from its aqueous solution by the 
addition of alcohol, or when ferrous sulphate is thrown out of 
solution by pouring its aqueous solution into alcohol. 

1497. Precipitation by reduction of temperature. — When 

saturated solutions are exposed to a reduction in temperature, 
a separation of solid matter may of course be expected, the 
result being either precipitation or crystallization, according to 
whether the solid is crystalline or amorphous. 

1498. Chemical Precipitation is always the result of a 
chemical reaction whereby either the dissolved matter or the 
solvent, or both, are changed into new compounds, the solids 
produced by this change being insoluble in the liquid. Chem- 
ical precipitation is generally the result of ''double decomposi- 
tion." 

1499. Precipitation resulting from slow chemical 
changes. — Precipitates are frequently formed in fluid extracts, 
tinctures, and solutions by chemical changes gradually produced 
under the influence of light, heat, contact with air, and the 
action of the dissolved substances upon each other or upon the 
solvent. 

1500. Precipitating jars are vessels of glass or stoneware 
somewhat narrower at the top than below, so that the precipi- 
tates produced in them may fall to the bottom without coming 
in contact with the sides. But these vessels are seldom used. 
Precipitations are performed in various kinds of vessels, from 
a little test tube to a large tank. -Beakers, wide-mouthed bot- 
tles, stone pots and barrels are the most common. 

1501. The physical properties of precipitates depend much 
upon the temperature and degree of concentration of the solu- 
tions employed in producing them. Strong and hot solutions 
make denser precipitates; dilute and cold solutions make bulk- 
ier, more finely divided, and lighter precipitates (1031). 



PHARMACY. 467 

CHAPTER LXXXII. 

METHODS OF EXTRACTION OF THE SOLUBLE MATTERS FROM PLANT 

DRUGS. 

1502. Extraction. — The various substances contained in 
plant drugs may be extracted by means of proper solvents or 
7iienstrua. 

The objects are to separate the active constituents from the 
inert, and to present the drug in a more convenient form for 
medicinal use. 

1503. Extract. — The product extracted from an organic 
substance by any simple solvent is called an extract. It is usu- 
ally a mixture of many constituents. 

The term is sometimes applied to the whole solution formed 
in the process of extraction, including all or nearly all of the 
solvent employed. 

Usually the term extract applies only to the residue obtained 
when the solvent has been more or less perfectly removed by 
distillation or evaporation. 

1504. Extracts prepared in the course of organic analysis are classified 
according to the solvents employed. Thus a water extract is one prepared 
with water, and hence containing chiefly water-soluble substances; an ether 
extract is one made with ether and containing ether-soluble constituents ; the 
terms benzin extract, alcohol extract, chloroform extract, etc., are respect- 
ively used in a similar manner. 

1505. The Extracts of Pharmacy are semi-fluid, soft 
solid, or dry preparations obtained by extracting the soluble 
constituents from drugs by means of simple solvents and evap- 
orating the solutions until the products have the required con- 
sistence. 

1506. Extractive. — The bulk of the medicinal extracts is 
usually made up of inert constituents common to all such prep- 
arations, especially to those made with water or with water and 
alcohol. These constituents, collectively, have received the 
name extractive. Often they do not exist in the drug in the same 
condition in which they are found in the extracts, having been 
materially altered in the process of extraction, mainly by the 
influence of heat and the exposure to air. 



468 PHARMACY. 

1507. Modifications of the extractive matter. — Whilst 
there is a general resemblance between the extractive of one 
extract and that of another, the character of the extractive 
varies with the drug, the menstruum, and the method of prepa. 
ration. 

1508. General properties of Extractive. — Extractive 
matter is soluble in water and in alcohol; in solution it is dark- 
ened by exposure to air when heated at or near the boiling point, 
and then undergoes partial decomposition, one of the products 
of this decomposition being a black or nearly black deposit 
which has received the name oiapotheme. It is stated that oxygen 
is absorbed and carbon dioxide given off during this change. 

1509. The apotheme is sparingly soluble in water, but 
more readily soluble in alcohol, and freely soluble in alkalies. 
The alkaline solution is reddish brown, and the apotheme is 
precipitated from it when the alkali is neutralized by an acid. 

In other respects the apotheme resembles humus, which is the 
principal constituent of the black soil formed by the slow decay 
of wood and leaves on exposure to air and moisture. 

1510. The various methods of extraction are: maceration^ 
digestion, infusion, decoction and percolation. 

1511. Maceration is the more or less prolonged action of 
a menstruum upon a drug without the application of heat. The 
drug is usually coarsely comminuted, and the temperature of 
the solvent is the common room temperature — usually about 
20 C. (68° F.), but in the summer season highei. 

The liquid extract obtained by maceration is called a macerate. 

In simple maceration the whole quantity of menstruum is at 
once mixed with the whole amount of the drug. 

In other cases the menstruum is divided into two or more por- 
tions, and the whole quantity of drug is macerated first with one 
portion, and, after separating the first macerate, is then macer- 
ated again with another portion, etc. This is more effective than 
to add all of the menstruum at once. The most common rule 
for what might conveniently be called re-maceration is to divide 



PHARMACY. 



469 



the menstruum into two portions, one consisting of two-thirds 
of the whole quantity and the second portion consisting of the 
remaining third, and to macerate the whole quantity of drag 
with the first portion of menstruum a given period, reserving 
this macerate, and then macerating the residue with the second 
portion of the menstruum for a period half as long as the first. 
Thus, if two pounds of drug is to be treated with fifteen pounds 
of diluted alcohol, it might be macerated first with ten pounds 
of the menstruum for six days, and afterwards with the remain- 
ing five pounds of the menstruum for three days, etc. 

A still more effective method of maceration consists in dividing 
both the drug and the menstruum, and to treat each portion of the 
drug in turn with each portion of the menstruum successively. 

1512. Digestion is a method of extraction similar to 
maceration in all respects except as to the temperature, which, 
in digestion, may be at any point between the .ordinary room 
temperature and the boiling point of water. Usually the tem- 
perature in digestion is not above 6o° C. (104. F.), but full 
water-bath heat is sometimes employed 

In digestion as well as in maceration the drug may either be 
treated with the whole quantity of menstruum at once, or with 
a portion at a time, or both drug and menstruum may be 
divided. (1511.) 

1513. The process of infusion is nearly the same as diges- 
tion. It is the immersion of comminuted drugs in boiling water 







Figs, 146 and 147, Squire's infusion pot, illustrating circulatory displacement. 
Fig. 148, Decoction vessel. 



470 PHARMACY. 

without maintaining the high temperature. Boiling water is 
poured upon the drug or species (1536), and the infusion 
vessel is set aside in any convenient place, the temperature of 
the contents being allowed to fall until it is the same as that of 
the atmosphere of the room unless the preparation is finished 
before that point is reached. 

The term " infusion" is also applied to the product obtained 
by the process here described, and even to certain macerates and 
percolates made with water and constituting finished prepara- 
tions. 

1514. Coction, or decoction, is the process of extracting 
soluble matters from plant drugs by exposing the latter to the 
action of water at its boiling point. This differs from infusion 
in that the boiling point is maintained from beginning to end in 
coction or decoction, while infusion only begins near the boiling 
point but ends far below it. 

Sometimes the amount of water added to the drug is twice 
the volume of the intended product, and the boiling continued 
until the volume is reduced by evaporation to the requisite 
measure. The general practice, however, is to add only an 
amount of water equal to the desired quantity of product, and 
to replace from time to time the water lost by evaporation, so 
as to maintain about the same volume to the end. 

15 15. Maceration, digestion, infusion and decoction are all 
employed, not only in the preparation of infusions and decoc- 
tions, but far more frequently in the preparation of extracts and 
other products. 

1516. The forces and phenomena concerned in the extrac- 
tion of the soluble contents of drugs by these several methods 
are various. Thus the menstruum is absorbed into the tissues 
of the particles of drug by capillarity (152 to 167); it passes' into 
closed cavities in the plant tissues by osmosis (169 to 178); lique- 
fies the soluble contents by solution (183); separates crystalloids 
from colloids by dialysis (179 to 182); the portions of solution 
thus formed mix with each other and with the menstruum on 



PHARMACY. 



471 



the outside of the particles of drug by diffusion (i6S);and the 
final liquid extract is then separated from the drug by expression 
or by displacement (1517). 

1517. Displacement.— Dissolved or readily soluble matters 
may be displaced or washed out from the insoluble matters with 
which they are associated, as from the tissues of druo-5. bv the 
descending current of a solvent. This is called displacement. 

Thus when a powdered drug has been macerated with its 
proper menstruum, in a percolator, until the soluble constituents 
have been reached and liquefied by the solvent, the solution thus 
formed may be " displaced '' from the mass bv adding more 
menstruum from above, and allowing it to descend slowlv. 

1518. Percolation is the extraction of the soluble constitu- 
ents from powdered organic drugs by solution and downward dis- 
placement with successive portions of menstruum, the process 
being conducted in suitable vessels 
(called percolators), and in such a manner 
that the first portion of liquid in its 
descent through the mass forms a highly 
concentrated solution, the density of 
the subsequent percolate decreasing 
regularly, until the drug is exhausted. 

The liquid extract which passes out 
of a percolator in operation is called a 
percolate. 

1519. The Pharmacopoeia describes 
a cylindrical percolator such as is suit- 
able for the official processes. Very 
similar to the pharmacopoeial percolator, 
but taller in proportion to its diameter. 
and more finished in its details, is the 
percolator designed by the author (Fig. 
149). The top of this percolator is 
ground smooth, so that by applying a 

little glycerin to it. and putting a plate Fig. i 49 . oidberg-'s percolator, 
of glass over it, the percolator is tightly closed. The stem is a 





47 2 PHARMACY. 

perfect bottle neck, so that the perforated rubber stopper is 
easily inserted in it. 

The rubber tube may be raised or lowered to lessen or 
increase the rate of flow of the percolate. 

1520. The special advantage of percolation over the simpler 
methods of extraction lies in the fact that the menstruum 
employed passes through many successive portions of drug so 
that each particle of the solvent is used many times over until 
it becomes so charged with dissolved matters that its solvent 
powers are utilized to the greatest practicable extent. In perco- 
lation, therefore, it is possible to completely exhaust the drug 
with a smaller quantity of menstruum than would be required 
to accomplish that result by maceration, digestion, or other 
methods. 

1521. Drugs a : : containing over fifty per cent, of extract- 
ive matter may be successfully percolated unless the soluble 
matter consists largely of resin or of gum. But extract-like 
drugs (opium, aloes, kino, catechu), gum-resins (like asafetida 
and myrrh), resins (like tolu, benzoin, guaiac) are not subjected 
to percolation, their tinctures and other extra ::s :e:ng made by 
maceration. 

1522. Tall percolators are to be preferred, because they are 
adapted to all kinds of drugs capable of being exhausted 
percolation. The taller the column of drug through which the 
menstruum must pass, the greater will be the quantity of solu- 
ble matter which that menstruum must take up in solution 
before it passes out of the percolator. But it is not possible to 
increase the height of the column of drug without limit, for not 
only would the apparatus be awkward to manage if too tall, 

too tall a column of a drug containing a large amounc of 
extractive would render the density of the solution so great 
before it reaches the bottom of the percolator as to arrest its 
farther descent. A tall percolator should be filled if the drug 
contains a comparatively moderate amount of soluble matter: 
but it should not be filled with a drug containing so large a 
quantity of extractive as to afford a solution too dense to pass 
through the column of drug without difficulty. 



?har;.:a:y. 



1523. Percolation is rendered effective by combining it wit 
maceration or digestion, which should be sufficiently long con- 
tinued to permit the menstruum to reach and liquefy the con- 
stituents of the drug, and to completely prepare the packed 
mass of drug for the displacement. Much of the soluble matter 
is in many cases at once dissolved and displaced by the descend- 
ing menstrnum, even before any liquid is permitted to pass out 
of the percolator, but the drug can not be exhausted by perco- 
lation without maceration except with a considerably greater 
amount of menstruum. 

1524. The several consecutive steps of the process : : extrac- 
tion by percolation are as follows: 1. the air-dry drug in a state 
of powder of suitable degree of fineness is moistened with a 
sufficient quantity of menstruum to render it uniformly damp 
when well mixed it; :. the dampened powder is then 
allowed to lie long enough to thoroughly absorb.the menstruum 
thus used, so that if the drug has a tendency to swell when 
moistened, this swelling of the particles may take place before 
tne drug is packed in the percolator (except in a few special 

:ises. where experience has shown that it is better to pack and 
percolate without delay); 3, the moist drug is then packed 
uniformly in the percolator, neither too firmly nor too loosely; 4, 
a sufficient quantity of menstruum is now poured upon the 
packed mass to saturate it from top to bottom, leaving a stratum 
of liquid standing over the top of the packed drug; 5, then the 
percolator is allowed to rest, with the lower end of the rubber 
tube raised and fastened to the top of the percolator while 
maceration takes place: 6. when the necessary period of macera- 
tion has been completed, the tube is let down and inserted into 
a suitable receiver (an ordinary Dottle is a very good receiver for 
this purpose), and the liquid in the percolator is permitted to 
run out. while more menstruum is added from time to time at 
the top, and the percolation is allowed to continue until the 
drug is exhausted. 

The percolate is sometimes collected all in one lot: sometimes 
the first percolate is set aside to be mixed with the subsequent 



474 PHARMACY. 

percolate only after the latter has been concentrated by evap- 
oration. 

1525. The scope of this book does not admit of greater 
detail in the description of this important process, but I regard 
it necessary to say to the student that the details of the process 
are governed by the nature of each drug operated upon, and 
that much practice is necessary to master them all, so that there 
is much to learn even after the general principles have become 
known to you. 

1526. Coarse powder is generally used when water or a 
weak alcoholic menstruum is used, while fine powder is used 
when the menstruum is strongly alcoholic. ■ But this question is 
also affected by the character and constituents of the drug 
regardless of the kind of menstruum employed. 

1527. Simple percolation is the process described in para- 
graph 1524. The whole amount of drug is packed in the perco- 
lator and the menstruum used is new menstruum — not a weak 
percolate from a previous percolation of the same drug. 

1528. In Re-percolation the drug and the menstruum are 
both divided into several portions, and each new portion of 
drug is completely exhausted by percolation with successive 
portions of liquid, the first portion being a weak percolate from 
a previous operation, the second a still weaker portion of the 
percolate from the percolation of the last previous lot of the 
same drug, and the last portion of menstruum used is new men- 
struum. 

1529. In making fluid extracts by re-percolation the per- 
colate is always collected in several portions. The first portion 
is finished fluid extract, the next portion is the first weak perco- 
late, then comes the second, and the third, and fourth weak per- 
colates — each collected separately, labeled properly, and put 
away to be used as menstrua in the next nercolation of an equal 
amount of the same drug. 

That the result will be uniform and the strength of the fluid 
extract exactly in accordance with the Pharmacopoeial standard. 
may be easily understood from the following supposed case: If 



PHARMACY. 475 

the quantity of drag operated upon each time be 10 pounds, and 
each io-pound lot be completely exhausted, and if it takes three 
portions of weak percolate of 10 pounds each, and one portion of 
new menstruum, also 10 pounds, to accomplish the complete 
exhaustion of each such lot of drug, then it follows that when 
ten such lots of the drug have been used we should have re- 
ceived to pounds of fluid extract from each lot, and would have 
used 10 pounds of new menstruum instead, at the end of each 
percolation, and in every case we would have 30 pounds of weak 
percolates on hand for next time. And the next ten lots would 
still leave us in precisely the same position. Therefore, if the 
work is well done, the result must be uniform and proper. 

1530. When concentrated liquid extracts, like our official 
fluid extracts, are to be prepared, re-percolation is an especially 
valuable process because it renders it unnecessary to resort to 
evaporation. 

1531. Complete saturation of the menstruum with dis- 
solved matter is rarely, if ever, accomplished in percolation, 
although it often happens that the density of the solution first 
formed is so great as to retard, if not wholly arrest, the flow of 
the percolate. 

1532. Complete exhaustion of the drug by percolation is 
frequently attainable without employing an unreasonably large 
amount of menstruum. It may be closely approximated in all 
cases, provided the work is skillfully done. 

1533. Marc — The residue left after extracting the soluble 
matters from drugs is called the marc. 

This marc retains a considerable quantity of the menstruum, 
held by capillarity. When, this menstruum is valuable it is 
usually recovered by distillation. 



476 



PHARMACY. 



CHAPTER LXXXIII. 

PHARMACEUTICAL PREPARATIONS CLASSIFICATION. 

I 534- Definite chemical compounds used as medicines, such 
as salts, haloids, acids, oxides, etc., whether inorganic or organic, 
have a comparatively simple pharmacy, because medicines con- 
sisting of only one substance are ready for use as soon as made 
into powder or solution, or even without further preparation. 
They may be used alone, or mixed with other substances, in any 
desired form. 

Organic crude drugs, however, like roots, barks, leaves, etc., 
which contain or consist of many different substances, some of 
which are medicinally valuable, others entirely inert, and still 
others objectionable, have a more complex pharmacy, because 
one of its most important objects is the separation of these sev- 
eral classes of constituents from each other with the view to the 
presentation of the active principles in the most convenient, 
effective and uniform condition. This involves the application 
of intelligent methods of extraction and concentration, and the 
production of classes of preparations wholly different from the 
chemicals. 

I 535« The pharmaceutical preparations might conveniently 
be classified into six groups, as follows: 

Preparations for Internal use. 

Class I. Dry and semi-solid preparations for internal 

USE MADE BY PROCESSES NOT INVOLVING EXTRACTION. They 

include: Species, powders, triturations, confections and electu- 
aries, masses, troches, boli, pills and granules. 

Class 2. Liquid preparations for internal use not 
made by extraction. — Solutions, waters, mucilages, syrups, 
honeys, glycerites, mixtures, emulsions and spirits. 

Class 3- Liquid extracts. — Infusions, decoctions, vin- 
egars, tinctures, wines, and fluid extracts. 

Class 4. Dry and semi-solid preparations made by 
processes which include extraction. — Extracts, abstracts, 
oleo-resins and resins. 



PHARMACY. 477 

Preparations for External use. 

Class 5- Solid and semi-solid preparations for exter- 
nal use. — Cataplasms, medicated papers and tissues, ointments, 
cerates, plasters and suppositories. 

Class 6, Liquid preparations for external use. — Gargles, 
lotions, injections, collodions, liniments. 



CHAPTER LXXXIV. 

preparations of class i (1535). 

I53&- Species are cut or otherwise coarsely comminuted 
drugs, single or mixed, intended for the preparation of teas, 
decoctions, bitters, poultices, etc. Breast teas, laxative teas, 
worm teas, etc., are common examples. 

I 537* Powders. — Simple powders, dispensed alone or mixed 
with other substances, must be quite fine and uniform. 

The Pharmacopoeia does not prescribe the particular degree of 
fineness for each drug commonly employed in the form of pow- 
der. Such powders should in no case be less fine than No. 60, 
and may with advantage be much finer; many drugs should be 
used in No. 100 to 120. 

Compound powders are usually composed of simple powders, 
but even moist ingredients are frequently "incorporated in them. 
The official compound powders are 9. 

They are prepared by trituration (1385). 

Whenever a small quantity of one substance must be mixed 
with a comparatively large quantity of another, the latter should 
be added, a little at a time, trituration following each addition. 

1538. Triturations are dilutions of potent remedies with 
sugar of milk in the form of powder, and containing ten per 
cent, of the active ingredient. 



47§ PHARMACY. 

There is i trituration in the Pharmacopoeia — that of elaterin. 

Other triturations may be made of tartrate of antimony and 
potassium, morphine, strychnine, or any medicinal agent, the dose 
of which is less than one grain. 

I 539- Confections and electuaries are solid or semi-solid 
strongly saccharine preparations. They are sometimes also 
called conserves. They are drugs or mixtures of drugs usually 
in a moist condition preserved and sweetened with sugar, honey 
or syrup. 

There are 2 such preparations in the Pharmacopoeia — the 
confection of rose, which is quite useless, and confection of 
senna. 

Electuaries are soft confections. 

Any powder made into a soft mass with any syrup or honey 
is a confection if it contains organic drugs to be preserved by 
the sugar, but an electuary if it consists of inorganic substances, 
simply massed and sweetened with the saccharine liquid. 

1540. Masses are mixtures of medicinal substances made 
of such consistence that they may be formed into pills. The 
Pharmacopoeia contains 3 masses — those of mercury and 
copaiba, and the "mass of carbonate of iron." 

1541. Troches are dry, or only slightly plastic, flat lozenges 
or tablets, made of medicines mixed with sugar, syrup, or 
extract of glycyrrhiza, and weighing usually from 10 to 20 
grains. 

The ingredients are massed with mucilage of tragacanth or 
some other suitable excipient, the mass is rolled out into sheets, 
and the troches are cut out with " lozenge cutters," the simplest 
of which is a tin tube. 

There are 16 different kinds of troches in the Pharmaco- 
poeia. 

1542. Boli, pills and granules are little, solid masses of 
medicinal substances, sufficiently firm to retain the form given 
to them. Boli maybe cylindrical, oblong, or round; pills may 
be round or oval; but granules are always round. Boli weigh 



PHARMACY. 479 

usually about 10 grains or more; pills from i to 5 grains, but 
most frequently from 2 to 3 grains; while granules weigh less 
than 1 grain. Practically, the difference between a bolus, a pill 
and a granule, is simply a matter of size. 

The kinds of substances entering into these preparations are 
powders, extracts, abstracts, oleoresins, chemicals, volatile oils, 
and many other materials. 

The ingredients are well mixed, and if they are not of such 
a nature as to form together a mass of suitable consistence, then 
one or more excipients must be added to mass them properly. 
Dry ingredients require moist excipients; moist or soft ingredi- 
ents require dry excipients; a wet mixture requires an absorb- 
ent excipient; insoluble and non-adhesive materials require 
adhesive excipients, etc. 

The mass must be firm, yet plastic enough to be easily iormed 
into pills; it must be perfectly uniform and smooth, and cohesive, 
but not sticky on the surface. 

To prevent pills from sticking to the fingers when they are 
being made, or to each other afterwards, they are dusted with 
some inert, insoluble, tasteless and inodorous powder. Such a 
powder, so used, is called a conspergative. 

For colored masses the best conspergative is lycopodium, 
while rice flour is the best for white pills. 

Among the best moist excipients are: water, diluted alcohol, 
glycerin, glucose, syrup, honey and mucilages of acacia and 
tragacanth. 

Among the best dry excipients are: tragacanth, acacia; slip- 
pery elm, althaea and glycyrrhiza; flour and starch; and milk 
sugar. 

Various special excipie?ifs are also employed. 

There are 15 different kinds of pills in the Pharmacopoeia. 



480 PHARMACY. 

CHAPTER LXXXV. 

PREPARATIONS OF CLASS 2 (1535). 

1543. Solutions {liquores) are a group of preparations con- 
sisting chiefly of ^water-solutions of non-volatile substances. " 

There are 25 such preparations in the Pharmacopoeia. 

''Solution of gutta-percha" is made with chloroform. 

Several of the official solutions are simply used as materials 
from which to make other preparations. 

It should not be forgotten that there are many " water solu- 
tions of non-volatile substances" which are not called "liquores" 
or solutions, as for instance the mucilages and syrups. 

Many of the liquores are simple solutions of definite chem- 
ical compounds, while others are of somewhat indefinite com- 
position and strength. Some are prepared by simple solution ; 
others by processes involving chemical reactions. 

1544. Waters (aqua) are defined as u water solutions of vola- 
tile substances." 

But they are a very mixed group of preparations. Most of 
them are aromatic waters — solutions of volatile oil in water. But 
such totally different preparations as chlorine water, ammonia 
water, etc., are also given the generic title "aqua." 

The aromatic waters are generally made by reducing the 
volatile oil to a very minute subdivision, and then bringing it 
into intimate contact with water. This may be accomplished 
in several ways. One method is to triturate the volatile oil with 
magnesium carbonate and a little water to a smooth, soft paste 
and then shake that with the rest of the water and filter. Cal- 
cium phosphate may with advantage be used instead of the 
magnesium carbonate, and tepid water gives a better result than 
cold water. 

The present Pharmacopoeia (1880) prescribes that the vola- 
tile oil be distributed on pure cotton (absorbent cotton), and 
that the water be percolated through the impregnated cotton. 

There are 14 kinds of "waters" in the Pharmacopoeia. 



PHARMACY. 481 

1545. Mucilages are solutions of gums or vegetable 
mucilage. All are made without the aid of heat. 

There are 5 official mucilages, those of acacia and tragacanth, 
and the less frequently used mucilaginous cold infusions of 
quince seed, slippery elm bark, and sassafras pith. 

Mucilages spoil rapidly and must therefore be prepared as 
wanted for use. 

1546. Syrups are concentrated solutions of sugar in water 
or in watery liquids, either with or without active medicinal con- 
stituents. Many syrups (as for instance the fruit syrups) are 
used simply as sweetening and flavoring additions to mixtures. 
Others are medicated with either inorganic chemical compounds 
in solution, or made with organic liquid extracts such as fluid 
extracts, infusions, etc. 

The sugar acts as a preservative as well as a sweetening 
agent in the medicated syrups. The amount of sugar necessary 
to protect the product from fermentation is about 65 per cent, 
when organic matters only are present, except that the presence 
of volatile oils and other preservative substances warrant some 
reduction of that proportion. But syrups containing inorganic 
chemicals will keep with much less sugar. 

Syrups should be kept in a cool place. 

There are 34 different syrups in the Pharmacopoeia. 

Honeys (mellita) resemble the syrups in that they are strong 
saccharine liquids. 

Honey of Rose is official. 

Hydrotnel is a mixture of equal volumes of honey and water, 
and oxymel a mixture of equal volumes of honey and diluted 
acetic acid. 

1547. Glycerites are glycerin solutions of medicinal sub- 
stances, or mixtures of glycerin with other substances for phar- 
maceutical uses. The only official glycerites now (1891) are 
glycerite of starch, which is used as a base for certain oint- 
ments, and glycerite of yolk of egg, which is used as an emulsi- 
fying agent. 



482 



PHARMACY. 



1548. Mixtures and Emulsions. 

Mixtures are liquid preparations containing insoluble matters 
in a fine state of division suspended in watery menstrua, or 
compound liquid preparations containing organic substances 
dissolved in watery fluids. The group of preparations which 
the Pharmacopoeia places together under the title Misturae 
consists of widely different products which might advanta- 
geously be subdivided. Thus there is one seed emulsion, two 
simple gum-resin emulsions, one compound gum-resin emul- 
sion, and one simple and two complex solutions, containing no 
undissolved matter, among the numbe 

An emulsion is a uniform liquid preparation containing finely 
divided insoluble matter (solid or liquid) held in suspension in 
a watery menstruum. The insoluble substances held in suspen- 
sion are usually either fixed oils, volatile oils^ or resins. Thus 
a seed emulsion holds fixed oil, an emulsion of a gum-resin holds 
volatile oil and resin, and cod liver oil, castor oil, olive oil, oil of 
almond, copaiba, oil of turpentine, guaiac, etc., may all be 
emulsified. 

To hold these substances in suspension for an indefinite 
period they must be in an extremely fine state of division, and 

an efficient eniulsifying agent must be 
present in sufficient quantity. 

The best emulsifying agents are 
gums and albuminoids. Acacia is by 
far the best; but tragacanth, yolk of 
egg, and Irish moss jelly are also used. 
A seed emulsion is formed when a seed 
is beaten up to a smooth, soft pulp 
with water, and more water added 
afterwards. Almond mixture (almond 

Fig. 150. An almond emulsion mortar. emulsiori) or a l mon d milk) is a per- 
fectly white, milk-like emulsion in which the fixed oil of the 
almond is emulsified and suspended, by the albuminoid emulsin, 
which is the white fleshy part of the almond. But the addition 
of acacia and sugar makes the preparation richer. The almonds 
are "blanched." An almond emulsion mortar is shown in Fig. 150. 




PHARMACY. 483 

Gum-resin emulsions are. formed whenever a gum-resin is tritu- 
rated with water. In such an emulsion the resin and volatile 
oil are emulsified and suspended by the gum — all of these con- 
stituents being contained together in the gum-resin. 

An emulsion of fixed oil is best made by first mixing the oil 
with half its weight of powdered acacia in a mortar, being very 
careful to leave no unmixed portions of either gum or oil; then 
add at once a quantity of water equal to $/% of the combined 
weight of the oil and gum used, and immediately proceed to mix 
all by an extremely rapid rotary motion of the pestle without 
pressure until the mixture thickens, becomes whitish, uniformly 
smooth, and gives a crackling sound under the pestle. The 
emulsification of the oil is then completed, and more water, if 
required, may afterwards be gradually added during constant 
stirring. The definite proportion of water first used is called 
the water of emulsification. A greater or a less proportion of water 
of emulsification than specified in this paragraph works less satis- 
factorily, and any considerable deviation defeats the object in view. 

Emulsions of volatile oils (as of oil of turpentine) and of 
oleo-resins (as of copaiba) are prepared in the same manner as 
emulsions of fixed oils, except that twice as large a proportion of 
powdered acacia is required, viz. : the same weight of acacia as 
of volatile oil or oleo-resin. 

The ordinary wedgewood mortars are well adapted for the 
preparation of emulsions of fixed and volatile oils / oleo-resins, 
and gum-resins. 

There are 11 different so-called " mixtures" in the Pharma- 
copoeia. 

1549, Spirits are "alcoholic solutions of volatile substances." 1 

Most of the "spirits" of the Pharmacopoeia are alcoholic 
solutions of volatile oils. But there are quite a variety of other 
liquids called spirits, as the spirit of ether, which is simply a 
mixture of alcohol and ether; spirit of ammonia, which is a 
solution of ammonia in alcohol; aromatic spirit of ammonia, 
which is a flavored solution of ammonium carbonate; spirit of 
chloroform; Cologne water; spirit of nitrous ether, which is 
to contain 5 per cent, ethyl nitrite; and brandy and whiskey. 



4 8 4 



PHARMACY. 



CHAPTER LXXXVI. 



PREPARATIONS OF CLASS 3 (1535). 

1550. Infusions are weak liquid watery extracts of plant 

drugs, prepared by infusion, maceration or percolation. 

They are rather crude unreliable preparations, because the 
menstruum and the methods of preparation are not such as to 
insure complete exhaustion of the drug. 

There are 5 official infusions. Boiling water is used in the 
preparation of three of them — those of Brayera. Digitalis and 
Senna (compound). 

Brayera is used in No. 20 powder, and the infusion is not 
strained ; in other words it is a crude mixture rather than an 
infusion, for water does not extract the active matter of Bray- 
era, and that is the reason why the preparation is not to be 
strained. 

Infusion of Digitalis is flavored with cinnamon and preserved 
with alcohol; the digitalis and cinnamon are used in No. 20 
powder. 




FigfS. 151 to 153. Infusion and decoction vessels. 

In the preparation of Compound Infusion of Senna, the Senna 
is used whole to avoid the extraction of much mucilage. The 
other ingredients in this preparation are magnesium sulphate 
manna, and fennel. 

Infusion of Cinchona is made by percolation with cold water, 






PHARMACY. 485 

acidulated with about one per cent, aromatic sulphuric acid. 
The bark is in No. 40 powder. 

Infusion of Wild Cherry is a cold water percolate of the bark 
in No. 40 powder. 

But the general formula of the Pharmacopoeia prescribes that 
in making any "ordinary infusion" the coarsely comminuted 
drug shall be put in a suitable vessel and ten times its weight of 
boiling water poured upon it, after which it is to "stand two 
hours," and is then strained. The Pharmacopoeia adds a 
"caution" to the effect that "the strength of infusions of ener- 
getic and powerful substances should be specially prescribed by 
the physician." 

1551. Decoctions are weak liquid water extracts of plant 
drugs, prepared by coction (15 14). 

Decoction of Cetraria and the Compound Decoction of 
Sarsaparilla are the only two now official (1891); 

The general official formula says that an "ordinary decoction " 
is to be made by putting the coarsely comminuted drug in a 
suitable decoction vessel, adding ten times its weight of cold 
water, covering well, boiling for fifteen minutes, then straining. 

The same "caution" is then added as in the case of infusions 
(i55o). 

1 55 2 - Vinegars (aceta) are liquid preparations prepared by 
extracting the active principles from plant drugs with diluted 
acetic acid. 

Some drugs containing alkaloids or acrid neutral principles 
are represented by preparations of this kind. 

They are prepared by percolation. 

Four are at present official, all of 10 per cent, strength with 
reference to the drug. 

1 553- Tinctures are defined as " alcoholic solutions of non- 
volatile substances.'" Sometimes they are defined as "alcoholic 
solutions of medicinal substances." But fluid extracts would be 
included under the first definition, and both fluid extracts and 
most of the spirits under the second. 



486 VHARMACY. 

With very few exceptions the official tinctures are alcoholic 
liquid extracts weaker than the fluid extracts. 

There are 73 tinctures now official (1891). 

Tinctures of crude plant drugs are made by percolation; 
those of resins, gum resins, extract-like drugs, and a few others 
that can not be percolated are made by maceration or by simple 
solution. 

Tinctures may be classified into alcoholic, which are made with 
a strongly alcoholic menstruum; hydro-alcoholic tinctures, which 
are made with diluted alcohol; a?nmoniated tinctures, made with 
aromatic spirit of ammonia, and ethereal tinctures, made with 
ether or containing a considerable portion of ether. 

Tinctures are not of uniform percentage strength as a class; 
they range from 5 per cent, to 50 per cent., the greater number 
being 10 or 20 per cent. 

Fifteen of the official tinctures are made from more than one 
ingredient aside from the menstruum; these are called compound 
tinctures. The others are simple tinctures. 

Among the official tinctures are included three that contain 
inorganic constituents, namely: the tinctures of iodine, ferric 
acetate and ferric chloride. 

The Pharmacopoeia gives a general formula for the prepara- 
tion of tinctures of fresh plant parts. This provides that the 
bruised or crushed plant drug shall be covered with twice its 
weight of alcohol and macerated 14 days, after which the liquid 
is expressed and filtered. 

1554. Wines are solutions or liquid extracts, the menstruum 
of which is wine. 

They are made by simple solution, or by maceration or per- 
colation. 

There are 11 official wines, including the three kinds of 
unmedicated w T ine. 

I 555- Fluid Extracts are liquid extracts of plant drugs 
so prepared that each Cubic centimeter represents the medici- 
nal contents of one Gram of drug. (This is practically minim 
for strain. ) 



PHARMACY. 487 

They are alcoholic, or hydro-alcoholic. 

Fluid extracts are the most concentrated liquid extracts of 
plant drugs that have ever been officially recognized, and they 
contain so large an amount of soluble matter in many cases 
that they require to be prepared with very great care, especially 
because the amount of final product is far less than the quan- 
tity of menstruum necessary to exhaust the drug, which neces- 
sitates the concentration of a portion of the liquid extract by 
evaporation to bring the whole volume within the prescribed 
limit. 

Fluid extracts are nearly all made by percolation. The first 
portion of percolate (to the amount of from r^ to T 9 o of the bulk 
of the final product) is set aside as soon as collected, and the 
remainder of the percolate is evaporated to a soft pasty extract, 
which is then dissolved in the reserved portion enough new 
menstruum being finally added to make the total volume of the 
product what it should be according to the pharmacopceial 
standard of strength — 1 Cubic-centimeter for each Gram of drug. 

There are 79 official fluid extracts. 



CHAPTER LXXXVII. 

PREPARATIONS OF CLASS 4 (1535). 

1556. Extracts are dry or moist solids, sometimes quite 
soft, prepared by extracting soluble matters from plant drugs 
with suitable menstrua, and evaporating the liquid extracts thus 
obtained until they have the required consistence. 

Whenever the solid extract yielded is capable of being 
rendered entirely dry without injury to its constituents, that is 
usually the course pursued. But when the extract can not be 
safely evaporated to dryness it is instead mixed with a small 



488 PHARMACY. 

quantity of glycerin to keep it permanently sufficiently moist 
and soft to be conveniently used. 

Dry solid extracts are generally reduced to powder. 

The yield of solid extract from plant drugs varies all the way 
from about 3 per cent, (in the case of physostigma) to about '40 
to 50 per cent, (in rhubarb and opium). 

Solid extracts are alcoholic, hydro-alcoholic^ or aqueous 
according to the menstruum used in their preparation. 

The menstruum used should be one which will extract all 
of the active or valuable constituents but at the same time as 
little as possible of other soluble contents of the drug in order 
that the product obtained may be reduced to a minimum of 
weight and a maximum of medicinal potency. 

The methods of extraction employed in the preparation of 
extracts are percolation, maceration, and digestion. 

The evaporation is produced by the heat imparted by the 
water-bath (1365). 

There are 32 official extracts. 

The aqueous extracts are those of : aloes, haematoxylon, 
opium, malt, taraxacum, gentian, glycyrrhiza, krameria, and 
quassia. 

There is one acetic extract, prepared with water containing 
over 23 per cent, official acetic acid ; this is the extract of col- 
chicum root (corm). 

One official extract is compound — the compound extract of 
colocynth. 

Solid extracts should, of course, not be made of drugs con- 
taining volatile active constituents, nor of drugs whose active 
principles are liable to be decomposed or damaged by exposure 
to heat. 

1557. Abstracts are powdered solid extracts containing 
added sugar of milk in such quantity as to make the product 
represent the medicinal activity of twice its weight of the crude 
plant drug. 

As they are dried and powdered, the menstruum used is 
nearly always undiluted alcohol, which renders the drying 



PHARMACY. 489 

process less risky than if a less volatile menstruum were 
employed 

The drug is exhausted by percolation, the evaporation is 
conducted at as low a temperature as possible, the drying 
facilitated by the addition of a portion of the sugar of milk, 
the rest of the sugar of milk being added after the drying so as 
to make the weight of the first product one-half of that of the 
drug used, and the abstract is finally reduced to a very fine 
powder. 

There are 11 abstracts in the present Pharmacopoeia (1891). 

Abstracts can be made of all drugs not yielding too great 
an amount of extractive, and not sensitive to the heat necessary 
to render the product dry enough to be reduced to fine powder. 

1558. Oleoresins are extracts made with stronger ether 
as the menstruum, and consisting chiefly of volatile oil and 
resin. 

They are made by percolation. The dry drug is packed in 
the percolator, and the menstruum then added, the whole 
apparatus (percolator and receiver) being tightly closed to 
prevent evaporation of the ether, the top of the percolator 
being connected by a bent glass tube with the top of the receiver 
to remove the pressure which would otherwise prevent the 
descent of the percolate. The ether is then removed by distilla- 
tion and evaporation. 

There are 6 official prepared oleoresins, which are fluid or 
semi-fluid. 

Stronger ether is prescribed as a menstruum Decause if a 
less volatile menstruum is used the volatile oil would be partly 
lost in the evaporation. 

1559. Precipitated Resins are made by exhausting resinous 
drugs by percolation or digestion with alcohol, distilling off 
most of the menstruum, and mixing the concentrated alcoholic 
tincture (or solution of resin) with a sufficient quantity of water 
to cause the resin to precipitate. The resin is then washed, 
dried and powdered. 



49° PHARMACY. 

The precipitated resins of the Pharmacopoeia are those of 
jalap, podophyllum and scammony. 

Resin of copaiba is the residue obtained when the volatile oil 
is distilled off from copaiba. 



CHAPTER LXXXVIIL 



PREPARATIONS FOR EXTERNAL USE. 

1560. Cataplasms or poultices are frequently employed, 
but there is no preparation of this kind now official. The most 
common cataplasms are "mustard plaster "and flaxseed poul- 
tice. 

1561. Medicated papers and tissues are much used. 
Paper, silk, and cotton fabrics are either impregnated with some 
medicament by immersion in its solution, or are painted over 
with it on one side. 

Mustard paper is official under the title of charta sinapis. 
The charta potassii nitratis is unsized paper dipped in a solution 
of potassium nitrate and dried; it is used by being burnt in 
the sick-room. 

Blistering tissues, antiseptic surgical dressings, etc., are 
also largely used, though not referred to in the Pharmacopoeia. 

1562. Ointments are usually soft solid fatty mixtures 
having a melting point near the temperature of the human body. 
They may be intended simply to render the skin soft and pliant, 
but are generally medicated with some substance intended either 
to be absorbed through the pores of the skin or to exert a local 
effect upon the parts to which they are applied. 

The materials of which the fatty basis of ointments are pre- 
pared are: lard, mixtures of lard and wax, and other mixtures of 
fats and resinous matters. But glycerite of starch and soft soap 
are also used in a similar manner. 

When solid fatty substances are to be mixed they are fused. 



PHARMACY. 491 

This insures an intimate intermixture. But when spermaceti^ 
wax, or other solid fats of high melting point are to be incor- 
porated with liquid fats, the solids being fused for this purpose, 
the liquid fats must also be warm and the mixture must be well 
stirred without interruption until cooled sufficiently to begin to 
thicken, for otherwise the firm fats of high melting point may 
congeal separately and render the product lumpy instead of 
smooth and uniform. 

Brisk stirring of a fused ointment or fatty mixture during 
the process of cooling renders the product lighter in color, softer, 
and bulkier. 

Ointments not made by fusion are prepared by trituration of 
the ingredients in a mortar, the medicament or active ingredient 
being mixed first with a small portion of the base or fat, and the 
remainder of the base added gradually. If the medicament is a 
solid it should be either finely powdered or dissolved in a small 
amount of a suitable solvent; but it is rarely practicable to dis- 
solve the active constituent before incorporating it in the oint- 
ment as only a very limited amount of liquid can be added. 

There are 26 official ointments. 

1563. Cerates differ from ointments mainly as to their melt- 
ing point and consistence. They do not melt at blood heat 
(37°C., or 98°F.), and are firmer than the ointments. Cerates 
are used as dressings. There are 8 official cerates. 

1564. Plasters (emplastrd) are generally firm, pliable, some- 
what adhesive solids, of such consistence that they must be 
softened by heat or melted before they can bespread upon skin, 
muslin or paper. They are not adhesive except when warmed 
to the temperature of the body, and are applied locally to the 
skin, sometimes simply to exclude air and protect the surface 
covered, and sometimes to medicate. 

" Adhesive plaster" is the resin plaster of the Pharmacopoeia; 
that is used to close the lips of wounds, and in other ways as a 
general " sticking plaster." Plasters are made of lead oleate 
and other metallic oleates, resins, gum-resins, and wax. They 



- :: 



PHARMACY 



are sometimes described as of three different kinds: i, plasters 
consisting mainly of metallic oleates, especially the oleate of 
lead; 2. resin plasters, like that of Burgundy pitch: 3, gum-resin 
plasters, like those of ammoniac and asafcetida. 

But there are also plasters prepared from rubber. 

Lead plaster consists mainly of oleate of lead, but contains 
also some stearate. 

Plasters containing resins and gum-resins have stimulant 
qualities. But more active medicaments are often introduced 
into plasters, as narcotic extracts, etc. When a solid extract is 
to be mixed with a plaster, the plaster must be melted by mod- 
erate heat, as over a water-bath, and the solid extract, previ- 
ously rubbed to a smooth, semi-fluid condition with dilute alco- 
hol, is then stirred in thoroughly. 

1565. Oleates of some metals, as lead, zinc, mercury, iron 
and copper, and oleates of some of the alkaloids, are employed 
externally as plasters or ointments. 

They are usually prepared in one of two ways: by double 
decomposition between sodium oleate (Castile soap) and a salt 
of the metal or alkaloid, or by dissolving metallic oxides or 
alkaloids in oleic acid. 

Some of the u oleates " employed are not pure, but the true 
oleates dissolved in or mixed with oleic acid or with fats. 

1566. Suppositories are firm solids formed into long 
cones with flat base and rounded apex. They are usually made 
of oil of theobroma, medicated as may be required, and weigh 
from 15 to 30 grains (1 to 2 Grams). 

The Pharmacopoeia gives a general formula for the prepara- 
tion of suppositories, directing that, unless otherwise prescribed 
bv the physician, they shall be made of oil of theobroma and 
shall each weigh 1 Gram. 

Oil of theobroma (or Cacao butter) is preferred because, 
while it is quite firm at ordinary temperatures, it melts rapidly 
at the temperature of the body. 

Suppositories are used to introduce medicinal substances 



PHARMACY. 493 

into the rectum, urethra, or vagina, their size and form being 
modified according to their intended use. 

The ingredients are mixed by trituration, and the cones are 
formed either by pressing the cold mass into moulds, or by melt- 
ing the mass and pouring it into chilled moulds, or they 
are formed out of the cold mass bv rolling, cutting and finishing 
them with the fingers. 

But oil of theobroma is not the only base used for suppos- 
itories. Glyco-gelatin is also used; it is a mixture of gelatin, 
glycerin and water in such proportions that when the mass is 
allowed to cool, after having been made with the aid of water- 
bath heat, it has the required consistence and firmness. 

Soap is also used in some suppository masses. 

There are no suppositories named in the Pharmacopoeia. 

1567. Gargles (gargarismatd) are washes for the throat. 
They are usually water solutions of astringent, antiseptic, or 
other medicaments. 

1568. Lotions are washes for local external use, consist- 
ing of medicated watery liquids or solutions. 

Eye washes are called collyria, and nasal lotions collunaria. 

1569. Injections are water solutions or other watery fluids, 
medicated or not, which are to be injected by means of syringes 
into cavities, as the rectum, vagina, urethra, the ear, or the 
nose. An injection for the rectum is called an enema. 

1570. Collodions are liquid external applications having 
for their base a solution of pyroxylin (or colloxylin) in a mix- 
ture of stronger ether and alcohol. By "pyroxylin " the Phar- 
macopoeia designates "soluble gun-cotton," which is known 
also by the name of " photographer's gun-cotton." 

Simple collodion is used to cover small surfaces or to close 
wounds, etc., instead of adhesive plaster and isinglass plaster. 
As the contraction caused by the ordinary collodion is some- 
times painful, additions are made to it to prevent it. The 
Pharmacopoeia has a "flexible collodion" containing castor oil 
and Canada turpentine to correct the difficulty referred to. 



494 PHARMACY. 

There are also two official medicated collodions — cantharidal 
collodion, used as a blistering application : and styptic collo- 
dion, used as an astringent. 

1571. Liniments are liquid, oily or alcoholic preparations 
for external application with or without friction. 

Fixed and volatile oils, and tinctures, fluid extracts and 
other alcoholic solutions are the most common ingredients 
employed. 

There are ten different liniments in the Pharmacopoeia. 



CHAPTER LXXXIX. 



IE LATINITY Of PHARMACEUTICAL NOMENCLATURE A.VD 
EXPRESSIONS. 

1572. Technical terminology is a necessity in every branch of science 
and art and in every profession or trade. Special words, or terms, are neces- 
sary to express specific things and ideas, and for every new thing or new idea 
a new word must be assigned to represent it. These technical terms are usu- 
ally constructed out of words selected from unspoken or dead languages; but 
they may be otherwise coined. The word telephone was constructed to desig- 
nate the valuable instrument which was only a few years ago undiscovered; 
if you did not now have that word " telephone," what would you call the 
instrument? It must have some name, and that name must be one which is 
not ambiguous; it must be sufficiently brief, and yet it must not be a word 
that has some other meaning than that which you want to impart to it. If we 
do not call the instrument a telephone, we must call it by some other equally 
new. suitable, unambiguous title. The same may be said of innumerable 
other technical terms, or words, or names. Technical terms are used in all 
branches of science, in law, in religion, in education, in the arts, in mechan 
ics, in the trades, in medicine, in pharmacy. Numerous technical terms 
which are not only thoroughly understood but at the same time indispensable 
to the specialists who use them, are altogether unintelligible to others. The 
pharmacist knows what a percolator is, but very few others know it. 

The words used to designate pharmaceutical processes, pharmaceutical 
apparatus and implements, drugs and preparations, and many other things 
pharmaceutical, are technical terms, and their construction and application con- 
stitute technical terminology. 



PHARMACY. 495 

1573. Latinic titles. — The titles and names given to drugs 
and preparations in the pharmacopoeias of the different nations 
are derived from various sources. Many are derived from 
Greek words, others from Latin, Arabic, Hebrew, Spanish, 
French, English, German, the tongues of savage tribes in various 
parts of the world, the names of countries, cities and towns, the 
names of men, etc. All these various technical terms or titles, 
regardless of their origin, are given a latinic form or termina- 
tion so far as this has been practicable, and all pharmaceutical 
titles not latinized or latinizable are indeclinable. 

But as the greater portion of the latinic titles consist of more 
than one word, one of which is in the genitive case, and as it is 
desirable to know the nominatives and genitives, singular and 
plural, of both nouns and adjectives, we will here present the 
rules, forms and terminations which are of common occurrence 
in the pharmacopoeias. 

1574. Latinic nouns have various terminations, and their 
declension depends mainly upon their terminations in the nom- 
inative. 

There are five declensions in Latin. They are characterized 
by the terminations given to the genitive singular, as follows* 

Termination of the 
Declension. genitive singular. 

1 ae 

2 i 

3 is 

4 us 

5 ei 

The endings of the nominatives of the names of each declen- 
sion vary greatly, and nouns with the same ending are often 
differently declined. 

Of the specific names of particular substances, as the names 
of metals and other elements, particular oxides, salts, acids, alka- 
loids, and any other specified drug, the plurals are of course not 
used. There can be but one iron, gold, mercuric iodide, mor- 
phine, squill, etc. But of the names of plant parts, classes of 



496 PHARMACY. 

chemical compounds, preparations, etc., the plurals are used, for 
we have several kinds of roots, seeds, tinctures, pills, ointments, 
oxides, acids, etc. 

I 575- First declension. — Nouns of the first declension 
end in a or e in the nominative singular, and are of the feminine 
gender. The only nouns ending in e, which are of interest to 
pharmacists, are aloe, mastiche and statice. 

The endings of nominatives and genitives, singular and 
plural, are: 

Singular. Plural. 

Nom. a or e ae 

Gen. ae or es arum 

Thus we have: 

Plural. 

Nom. Gen. 

Herbae Herbarum 

Pilulae Pilularum 

Tincturae Tincturarum 

not used 

Rosae Rosarum 

not used 
tt tt 

Examples of nouns of the first declension are: Acacia, aqua, 
cera, charta, herba, manna, massa, mistura, pasta, pilula, resina, 
rosa, tinctura; aloe, mastiche. 

1576. Second declension. — Nouns of the second declension 
ending in us or OS are masculine; those ending in um or on are 
neuter. But alnus, juniperus, prunus, sambucus and ulmus, all 
of which follow this declension, are feminine. 

The endings of the nominatives and genitives, singular and 
plu-al, are: 

Singular. Plural. 

Masc. Neuter. Mate. Neuter 

Nom us or os um or on i 

Gen i orum 



Singular. 




Nom. 


Gen. 


Herba 


Herbae 


Pilula 


Pilulae 


Tinctura 


Tincturae 


Cera 


Cerae 


Rosa 


Rosae 


Soda 


Sodae 


Aloe 


Aloes 





PHARMACY 




497 


Thus we have 








Singular, 






Plural. 


Nom. 


Gen. 


Nom. 


Gen. 


Bolus 


Boli 


Boli 


Bolorum 


Syrupus 


Syrupi 


Syrupi 


Syruporum 


Acidum 


Acidi 


Acida 


Acidorum 


Vinum 


Vini 


Vina 


Vinorum 


Prinos 


Prini 




not used 


Diospyros 


Diospyri 




a 


Eriodictyon 


Eriodictyi 




a 


Erythroxylon 


Erythroxyli 




a 



Examples of nouns of the second declension: Bulbus, cor- 
nus, trochiscus, caryophyllus, crocus, humulus, hyoscyamus, 
rubus; ceratum, extractum, folium, lignum, oxidum, chloridum, 
chlorum, iodum, glycerinum, oleum, rheum; toxicodendron, 
haematoxylon. 

I 577- Third declension. — Nouns of the third declension 
have many different terminations in the nominative singular, 
and they may be of any gender. Among the common endings 
of words of this declension are as, is, or, er, io. 

The ending of the genitive singular is is, and in the plural 
the nominative ends in es, but occasionally in ata, and the gen- 
itive in um or sometimes ium. 

The following examples are probably sufficient to show the 
general modes of changing the case-endings: 





Singular. 




Plural. 


Nom. 


Gen. 


Nom. 


Gen 


Pars 


Partis 


Partes 


Partium 


Citras 


Citratis 


Citrates 


Citratum 


Acetas 


Acetatis 


Acetates 


Acetatum 


Sulphas 


Sulphatis 


Sulphates 


Sulphatum 


Sulphis 


Sulphitis 


Sulphites 


Sulphitum 


Nitris 


Nitritis 


Nitrites 


Nitritum 


Arsenas 


Arsenatis 


Arsenates 


Arsenatum 


Arsenis 


Arsenitis 


Arsenites 


Arsenitum 


Pulvis 


Pulveris 


Pulveres 


Pulverum 


Liquor 


Liquoris 


Liquores 


Liquorum 



498 


PHARMACY. 




Singular. 


Plural. 


Nom. 


Gen. 


A T om . 


Gen. 


Lotio 


Lotionis 


Lotiones 


Lotionum 


Emulsio 


Emulsionis 


Emulsiones 


Emulsionum 


Mucilago 


Mucilaginis 


Mucilagines 


Mucilaginum 


Sapo 


Saponis 


Sapones 


Saponum 


Cataplasma 


Cataplasmatis Cataplasmata 


Cataplasmatum 


Tuber 


Tuberis 


Tubera 


Tuberum 


Radix 


Radicis 


Radices 


Radicium 


Cortex 


Corticis 


Cortices 


Corticium 


Flos 


Floris 


Flores 


Florum 


Semen 


Seminis 


Semina 


Seminum 


Summitas 


Summitatis 


Summitates 


Summitatum 


Stigma 


Stigmatis 


Stigmata 


Stigmatum 


Rhizoma 


Rhizomatis 


Rhizomata 


Rhizomatum 


Stipes 


Stipitis 


Stipites 


Stipitum 


Borax 


Boracis 


not 


used 


Calx 


Calcis 




a 


Rumex 


Rumicis 




a 


Pix 


Picis 




M 


Macis 


Macidis 




u 


Berberis 


Berberidis 




a 


Adeps 


Adipis 




it 


Asclepias 


Asclepiadis 




a 


Juglans 


Juglandis 




« 


Piper 


Piperis 




u 


Zingiber 


Zingiberis 




a 


Mel 


Me His 




n 


Mas 


Maris 




a 


Lac 


Lactis 




tt 


Chloral 


Chloralis 




« 


Digitalis 


Digitalis 




K 


Alumen 


Aluminis 




<< 


Rhus 


Rhois 




tt 


Erigeron 


Erigerontis 




it 



PHARMACY. 499 

1578. Fourth Declension. — The only nouns of the fourth 
declension which occur commonly in pharmaceutical nomencla- 
ture are spiritus, fructus, cornus and quercus. They are declined 
as follows: 

Singular. Plural. 

Nom. Gen. Norn. Gen. 

Spiritus Spiritus Spiritus Spiritu 

Fructus Fructus Fructus Fructuum 

Cornus Cornus not used 

Quercus Quercus " 

x 579- Fifth Declension. — Prooably the only word in 
pharmaceutical terminology which comes under the fifth declen- 
sion is the title species, which is only used in the plural. It is 
applied to mixtures of cut, crushed or ground drug intended to 
be used for teas, decoctions, bitters, etc. The nominative is 
species, and the genitive specierum. 

1580. Indeclinable nouns. — There are several indeclinable 
nouns used as titles or parts of titles for medicinal substances. 
They are alcohol, amyl, azedarach, buchu, catechu, coca, curare, 
elemi, ethyl, jaborandi, kamala, kino, kousso, matico, menthol, 
methyl, phenol, phenyl, sago, sassafras, sumbul and thymol. 

1581. The genitives are used in formulas, prescriptions, 
titles of two nouns, and in other instances where the genitive or 
possessive case is employed or understood. Rhei is the geni- 
tive of rheum, rhubarb; it means of rhubarb, and is, therefore, 
used in the compound title tinctura rhei, which means tincture 
of rhubarb. In a formula or prescription the words "take of 
rhubarb" would in Latin be translated "Recipe Rhei." 

Oleum ai?iygdal<z means "oil of almond." 

Oleu7?i amygdalarum means "cil #/ almonds.'' 

Arnica means "arnica." 

Arnicoz radix means " root #/ arnica " or arnica root. Arnicoz 
flores means "flowers of arnica," or arnica flowers. 

Erigeron mGans "erigeron"* Oleum erigerontis means " oil of 
erigeron." 



5°° 



PHARMACY. 



Folia belladonna, or Belladonna folia (both forms are equally 
correct) means "leaves of belladonna." Tinctura belladonna • 
foliorum means "tincture of the leaves of belladonna." 

R Tincturae belladonnae foliorum unciam unam means 
"take of the tincture of the leaves 0/ belladonna one ounce." 

1582. Adjectives. — The adjectives commonly used in phar- 
maceutical nomenclature are not many. They are declined 
in accordance with the first declension when of the feminine 
form ending in a; the second declension when of the masculine 
form ending in us, or the neuter form ending in umj the third 
declension when of the masculine form and ending in er or is; 
of the feminine form and ending in is, and of the neuter form 
and ending in e. 

Certain adjectives ending with the letter s, or x, have the 
same ending for all three genders in each case, as simplex, 
simplicis, simplices, pi. simplicia, simpliciorum, simplicia, etc. 

In the comparative degree the adjectives have the endings 
-ior in the masculine and feminine forms, and -ins in the neuter; 
and in the superlative degree the ending -issimus for the mascu- 
line, -issima for the feminine, and -issimum for the neuter form. 

Thus: 

Masculine. Feminine. Neuter, 

Positive Fortis Fortis Forte 

Comparative Fortior Fortior Fortius 

Superlative Fortissimus Fortissima Fortissimum 

1583. Numerals. — The Roman notation is commonly used in prescrip- 
tions. They are: 



I 


I 


XI 


II 


XL 


40 


II 


2 


XII 


12 


L 


50 


III 


3 


XIII 


13 


LX 


60 


IV 


4 


XIV 


14 


XC 


90 


V 


5 


XV 


15 


C 


100 


VI 


6 


XVI 


16 


cx 


ITO 


VII 


7 


XVII 


17 


cc 


200 


VIII 


8 


XVIII 


18 


D 


5OO 


IX 


9 


XIX 


19 


DC 


60O 


X 


10 


XX 


20 


M 


I, OOO 



PHARMACY. 



;oi 



The Roman card'nals 


and ordinal? 


are as follows 




Cardinals 




Ordinals. 




Unus. una, unum 


i 


Primus 


First 


Duo, duae, duo 


2 


Secundus 


Second 


Tres. tres, tria 


3 


Tertius 


Third 


Quatuor 


4 


Qaartus 


4th 


Quinque 


5 


Quintus 


5 th 


Sex 


6 


Sextus 


6th 


Septem 


" 7 


Septimus 


7 th 


Octo 


3 


Octavus 


8th 


Xovem 


9 


Xonus 


qth 


Decern 


io 


Decimus 


10th 


Undecim 


ii 


Undecimus 


nth 


Duodecim 


12 


Duodecimus 


12th 


Tredecim 


13 


Tertius decimus 


13th 


Ouatuordecim 


14 


Quartus decimus 


14th 


Quindecim 


15 


Quintus decimus 


15th 


Sexdecim 


16 


Sextus decimus 


16th 


Septendecim 


17 


Septimus decimus 


17 th 


Duodeviginti 


iS 


Duodevicesimus 


i3th 


Undeviginti 


19 


Undevicesimus 


19th 


Viginti 


20 


Vicesimus 


20th 


Viginti unus 


21 


Vicesimus primus 


2ISt 


Viginti duo 


22 


Vicesimus secundus 


22d 


Triginta 


SO 


Tricesimus 


30th 


Quadraginta 


40 


Ouadragesimus 


40th 


Quinquaginta 


SO 


Quinquagesimus 


50th 


Sexaginta 


60 


Sexagesimus 


60th 


Septuaginta 


70 


Septuagesimus 


70th 


Octoginta 


SO 


Octogesimus 


80th 


Xonaginta 


90 


Xonagesimus 


90th 


Centum 


IOO 


Centesimus 


100th 


Ducenti 


200 


Ducentesimus 


200th 


Trecenti 


30O 


Trecentesimus 


300th 


Quadrigenti 


40O 


Quadringentesimus 


400 th 


Quingenti 


500 


Quingentesimus 


500th 


Sexcenti 


600 


Sexcentesimus 


600th 


Septingenti 


700 


Septingentesimus 


700th 


Octingenti 


Soo 


Octingentesimus 


Sooth 


Xongenti 


900 


Xongentesimus 


900th 


Mille 


000 


Millesimus 


1, oooth 



502 



PHARMACY. 



Bis means twice. 

Ter and Iris mean thrice. 

Simplex means simple. 

Duplex means double. 

Triplex means triple. 

Quadruplex means quadruple. 

The ordinals are all declinable like adjectives, thus: 
Primus prima 

Secundus secunda ( 

The cardinals are indeclinable, except unus, duo, and Ires, 
declined as follows: 



Nom. 
Gen. 

Accus. 

Nom. 
Gen. 

Accus 

Nom. 

Gen. 

Accus. 



Masc. 
unus 
unius 
unum 

duo 

duorum 
duos 

tres 

trium 

tres 



Fern. 
una 

unius 
unam 

duae 

duarum 

duas 

tres 

trium 
tres 



primum 
secundum 
which are 

Neuter. 
unum 
unius 
unum 

duo 

duorum 
duo 

tria 

trium 

tria 



PHARMACY. 503 

CHAPTER XC. 
WEIGHTS AND MEASURES. 

THE METRIC SYSTEM. 

Linear Measure. — The Meter (equal to 39.37 .nches) is the 

primary unit. 

1 Kilometer (km) is equal to 1,000 meters. 

1 Meter (M) is equal to 100 centimeters (cm) or 1,000 milli- 
meters (mm). 

Measures of Capacity. — The Liter (equal to 33.815 U. S. 
Apothecaries' Fluid Ounces) is the primary unit. 

1 Liter (L) is equal to 1,000 cubic-centimeters (cm). 

Units of Weight. — The Gram is the primary unit. 

1 Kilogram (kGm) is equal to 1,000 Grams. 

1 Gram (Gm) is equal to (10 decigrams, or to 100 centigrams, 
or to) 1,000 milligrams (mGm). 

In writing quantities by weight or measure in the Metric 
System, the common Arabic numerals are used, and the num- 
bers are always placed before the signs or terms which represent 
the units, thus: 5 C.c, 15.500 Gm, 500 mGm, etc. A comma 
should never be used instead of the period to point off decimals, 
and the units chosen to express the quantities or values should 
be sufficiently small to avoid fractions as far as possible. 

The only units necessary in medicine and pharmacy are: the 
Liter, Cubic-centimeter, Kilogram, Gram, and Milligram. 

The Cubic-centimeter is abbreviated to C.c, the Gram to 
Gm, and the milligram is abbreviated to mGm. (See Dose 
Table, Chapter LXXV). 

THE APOTHECARIES' SYSTEM." 

Fluid Measure. — The units are: The Minim (m). 
The Fluid drachm (f 3), equal to 60 minims. 
The Fluid ounce (fl), equal to 8 fluid drachms, or 480 

minims. 
The Pint (O), equal to 16 fluid ounces. 
The Gallon (C), equal to 8 pints. 



504 PHARMACY. 

Weight. — The units are: 
The grain (gr.) 

The Scruple (3), equal to 20 grains. 
The Drachm (3), equal to 3 scruples, or to 60 grains. 
The Ounce (3), equal to 8 drachms, or 24 scruples, or 
480 grains. 

In writing quantities in terms of Apothecaries' Weights and 
Measures, Roman numerals are used, and the numbers are always 
placed after the signs or terms which represent the units, thus: 
gr. X; Sj; 3 vj; I iv; mXXX; f 3ij; flviij, etc. 

AVOIRDUPOIS WEIGHT. 

The Commercial Weight in common use in the United States 
is the Avoirdupois Weight of Great Britain, the units of which 
are as follows: 

The grain (gr.) [This grain is identical in value with the 
• Apothecaries' grain and the grain of Troy Weight.] 
The Ounce (oz.), equal to 437-J grains. 
The Pound (ft)), equal to 16 ounces, or 7,000 grains. 

RELATIONS OF WEIGHTS AND MEASURES OF THE SEVERAL SYSTEMS. 

Measure. Weight. 

1 C.c, of pure water weighs 1 Gm 

1 Liter " " " 1 Kilogram 

1 Minim (U. S.) of pure water weighs 0.95 grain 

1 Fluidrachm " " " " 56.96 " 

1 Fluidounce " " " " 455.69 " 

96 U. S. fluidounces of pure water weigh 100 avoirdupois ounces. 

Weight. 

1 Gram of pure water measures 

1 Kilogram 

1 Grain of pure water measures 

1 Drachm 
1 Ounce 





Measure. 
1 C.c. 
1 Liter 


I. 

5°5' 


05 minims 

2 

6 



PHARMACY. ^05 

Relations of Metric Units and the Old Units* 

1 Meter = 39-37 inches 

1 Centimeter = about 0.4 inch 
1 Millimeter = about 0.04 inch 

t Liter = about 34 U. S. fluidounces 
1 C.c. = about 16 U. S. minims 

1 Kilogram = about 35 avoirdupois ounces 
1 " = about 32 apothecaries' ounces 

1 Gram = about 16 grains 

1 Milligram = about -^ T grain 
1 Inch = about 25 millimetres 

1 U. S. Fluidounce = about 30 C.c. 
1 " Minim = about 0.06 C.c. 

1 Apothecaries' Ounce = about 32 Gm 

1 " Drachm = about 4 Gm 

1 Grain = about 64 milligrams 

1 Avoirdupois Pound = 453.6 Grams 
1 Ounce = 28.35 " 

Imperial Fluid Measure. 

(Great Britain). 
The minim (m), equal to 

The Fluidrachm (f 3), equal to 60 such minims. 
The Fluidounce (f §), equal to 8 such fluidrachms, or 

480 minims. 
The Pint, equal to 20 such fluidounces. 
The Gallon, equal to 8 such pints. 

1 Imperial Gallon is the volume of 10 avoirdupois pounds of 
water at 62 F. 

1 Imperial Fluidounce of water weighs 1 avoirdupois ounce. 



INDEX. 



A bietic anhydride 381 

Absolute tempetature 80 

Absolute zero 80 

Abstracts 489 

Acacia 335, 378 

Aceta 486 

Acetates 271 

Acetic acid 219, 282 

Acetones 282, 287 

Acetyl 217 

Acid, acetic 219, 282 

benzoic 382 

boric 190 

carbolic 281 

chrysophanic 351 

citric 284 

formic 282 

fruit c!40 

hydriodic 182 

hydrobromic 182 

hydrochloric 140, 181, 254 

hydrocyanic 185 

hydrosulphuric 178 

lactic 283 

malic 284 

muriatic 132, 133,181 

nitric 133, 183, 185, 254 

of air 132 

oleic 339 

oxalic 283 

oxy-oleic 339 

palmitic 339 

phosphoric 188 

prussic '85 

radicals 219, 251, 253 

residues 219, 25:, 253 

stearic 339 

succinic 284 

sulphuric 138, 178, 254, 262 

sulphurous 178 

sulphylricng 

tannic 344 

tartaric ^83 

valeric 353 
Acid-forming- oxides 235 

radicals 216, 253 
Acidity 249 
Acids 131-133, 216, 260-255 

action on metals 254-2o5 

carbonates, hydrates and ox- 
ides 255 

and alkalies 131-133 

and bases, reactions 253 

basicity 251 

classes 250 _ 

formulas 218, 219, 220 

hydrogen 253 

hydroxyl 251, 252 



Acids, nomenclature 294, 295 

of chlorine 181 

organic 282, 284, 287, 333, 34J 

oxygen 251, 252 

strength, relative 133 

true 251 
Acidulous radicals 222, 223 
Aconite 345 
Aconitine 345 
Acorin 347 
Ac fid drugs 342, 343 
Actinic rays of light 102 
Active principles of drugs 333 
Adeps 385 
Adjectives 501 

ending in "-ic" and - l -ous"292, 293 
Adhesion 12, &5 

in chemical reactions 130 
Adhesiveness 35 
Adhesive plaster 492 
Affinity 8, 12, 1 13, 1 3, 1C4. 1?5 

predisposing 131 
Affusion and decantation 311. 312 
Aggregation, states of 14, 17, 90, 164 
Air, humidity of 97 

pump 72, 73 

saturated -with vapor 97 

temperature of 97 

volume of one grain of 12 
Albumen 450 
Albumin 333, 338. 450 
Albuminoids 333, 338 
Alcohol as a solvent 441 
Alcohols 215, 280, 281, 266 

names of 295 
Alcohol-soluble sul stances 442 
Aldehydes 282, 286 

names of, 295 
Alkali compounds 21? 
Alkalies 91. 13 , 132, 133, 247 

and acids 131-133 

fixed 91 

relative strength of, 133 
Alkali metals 196, 197 

mineral e 132 

vegetabile 132 

volatile 13i 
Alkaline earth metals 200 
Alkaloidal salts 28J 
Alkaloids 184, 288, 333, 344, 345 

names of, 295 
Allium 345 
Allotropy 191 
Alloys 92, 167, 168 
Almond mi*k 482 

mixture 482 
Almonds 371 
Aloes 371 



507 



5 o8 



INDEX. 



Aloin 375 

Alteratives 393 

Althaea 346 

Alum 204 

Aluminum and compounds 203, 204, 205 

Amalgams 167, 168 

American hellebore 354 

Amides 288, 345 

Amines 288, 291, 345 

Ammonia, 176, 184, 185, 200, 248 

Ammoniac 379 

Ammoniated mercury 241 

Ammonium and compounds 200 

Amorphous bodies 15, 20 

Amygdala 371 

Arnygdalin 358, 371 

Aroyl 217 

Amylaceous matters 334 

Amylum 378 

Anaesthetics 394 

Analgesics 394 

Analysis 126, 127 

Anaphrodisiacs 395| 

Anatomy 327, 328 

Angles of crystals 18 

Anhydrides 133, 235 

of chlorine 180 

of sulphur 178 
Anhydrous crystals 25 
Animal drugs 391 

kingdom 109 
Anise 367 
.anodynes 394 
Antacids 397 
Anthemis 361 

Antimony and compounds 186, 189 
A. timonyl 217 
Antipyretics 394 
Antiseptics 397 
Antispasmodics 394 
Aphrodisiacs 395 
Apothecaries' weights and measures, 

505, 506 
Apotheme 468 
Aqua regia 132, 210, 255 
Aquae 480 
Aqueous fusion 129 
Arputin367 

Archimedes law of, 61-66 
Areometer 66 
Argols 198, 273 
Arnica flowers 361 
Aromatic drugs 341 

waters 480 
Arseuat' s 270 

Arsenic and compounds 186, 188, 189, 270 
Arsenites 270 
Arsine 189 
Arrow-root 378 
Arterial sedativeg 395 

stimulants 395 
Artiads 152 
Asaf etida 380 
Asnaragin 343 
Aspidium 346 
Aspidosperma 355 
Aspidospermine 355 
Astringents, 344. 396 
Atmosphere 67-70 

height of 69, 94 

weight of 68 
Atmospheric pressure 67-73, 94 



Atomic attraction 8, 12, 113, 123, 124, 125 

heat 144 

matter 6, 147 

motion 13 

theory 142 

value 150-158, 233 

weight 143, 144, 146, 149, 169 
table of 149 
periodicity 169 

weights, relation of. to polarity 138 
Atomicity 147, 151, 224 
Atomizers 71 
Atoms 5, 6, 112-114, 116, 117, 124, 142-147 

diameter of, 142 

directly united 227 

free 147 

kinds of, 112 

molecules and masses 116-117 

valence of, 150-158 

volume of, 145 

weight of, 142 
Attraction 8-12 

atomic 113, 123-125 

chemical 113, 123-125 
Atropine 346, 363, 366, 373 
Attar 340 

Auramii amari cortex 3"5 
Avogadro's law 146, 147 
Avoirdupois weight 505 
Axes of crystals 22 



Balance 55, 56 

hydrostatic 55, 62 
" Balsam of copaiba " 384 

fir 384 

Peru 3S3 
Balsamic resins 342 
Balsams 34 1 

Barium and compounds 202 
Barks ->31, 354 
Barometer 68 
Barometric pressure 67-73 
Base, physical 50 
Base residues 249 
Bases 133, 247, 250, 253 

reactions of, with acids 253 
Basicity of acids 251 
Ba-ic oxides 2b5 
BasylODs radicals 220, 221, 2^2 
Baths 426, 427 
Beakers 443 
Beet-root sugar 336 
Belladonna leaves 363 

root 346 
Belladonnine 346, 363 
Benne oil 386 
Benzoates276 
Benzoic acid 382 
Benzoin 382 
Berberine 348 
Berthollet's laws 297-300 
Berzelius' hypothesis 136 
"Bi-"292 
Bibasic acids 251 
Bicarbonates 268 
Bichromate of potassium 270 
Binary compounds 234. 291 
Biniodide of mercury 245 
" Bis" ^92 

p ismuth and compounds 186, 190 
B;smuthj'1217 



[NDEX. 



509 



Bitter orange peel 355 

tonics 393 
Bivalent radicals 152, 153 
Black color 100 
Blackberry root bark 359 
Bleaching powder 181, 262 
Blennorrheas 396 
Bloodroot 351 
Blue flag 349 
Body, definition of 1 
Boiling 451 

Boiling points 75, 90, 93, 94, 95, 451 
Boli 478 
Bonds 128, 153, 155, 227, 234 

self -saturation 155 
Bone Ash 201 
Bones, calcined 201 
Boneset 360 
Borates 269 
Borax 190 
Boric acid 190 
Boron 190 
Botany 323 
Brahma s press 60 
Brayera 361 
Brimstone 177 
Britileness7 
Bromides 243, 244 
Bromine 181 
Brucinc 272 
Buchu 363, 364 
Buckthorn bark 357 
Ru lbs 331 

Bunsen burners 424, 425 
Buoyancy of fluids 61 
Burners 424, 425 
Butter of cacao 386 
Buxine350 
Bye-product 309 

Cacao butter 386, 493 

Calabar bean 372 

Calabarine 373 

Calamine 20t 

Calamus 346 

Calcination 201, 429 

Calcium and compounds 201, 202 

Calcspar 19 

Calisaya bark 356 

Calomel 140, 2i8, 240 

Calories HI 

Calumba 347 

Calx 201 

Cambogia 380 

Camphor 390 

Canada turpentine 384 

Cane sugar 3 6 

Cannabis indica 360 

Cantharis 391 

Capillarity 33-41, 470 

Capsaicin 368 

Capsicum 367 

Caraway H68 

Carbohydrates 287, 288 

Carbolic acid 281 

Carbon 138, 191 

compounds 191-193 
Carbon disulphide 238 

group 194, 195 
Carbonate^ 212, 268, 269 



) Carbonization 428 
Caroonyl217^8-5 
Carboxyl 2S2 
Cardamom 368 
Cardiac sedatives 395 

stimulants 395 
Cardinals 502, 503 
Carminatives 395 
Carrageen 374 
Carum 368 
Caryophyllus 362 
Cascara sagrada 358 
Cassia cinnamon 356 
Castor oil 339. 386 
Cataplasms 491 
Cathartics 395 
Cathartin351,366 
Catechin 375 
Catechu 3*5 
Caustic, lunar 209 
Cayenne pepper 367 
Cells, electric 105 
Cellulin,333 334 
Cellulose 333, 534 

group 288 
Cement, 35 36 
Center of gravity 49 
Centigrade thermometer 77 
Centigram 504 
Centimeter, 504 506 
Centrifugal force 49 
Cera 385 
Cerates 492 
Cetaceum 385 
Chains 228, 229, 277 
Chalk 01 
Chamomile 361 

German 363 
Chartse 49 
Chemical affinity 8, 12, 113, 123-125 

attraction 113, 123-125 

changes 112, 119-123 

compounds 115, 116, 139 

constituents of drugs 332 

decomposition 119, 127, 134 

energy 113, 123-125 

equations 161, 162 

experiments 121. 122 

force 113, 123-125 

formulas 159 

nomenclature 289 

notation 158 

phenomena 118, 119-123 

polarity 125, 135 

properties 118 

rays of light 102 

reactions 119-123, 125-131, 225 

solution 439 

symbols 158 
Chemicals 318 

Chemism 76, 113, 123, 124, 125, 128, 129, 150 
Chemistry 6, 118, 133,134 

organic 192 

pharmaceutical 318 
Chenopodium 368 
Chinese cassia 357 
Chlorates 261, 262 
" Chloride of lime" 181, 262 
Chlorides 212, 240, 241-243 

of manganese 141 



5 IQ 



INDEX. 



Chlorine 155, 180, 181 

negative loo, 180 

oxides of 141, 180 

positive 155, 180 

valence 177, 178 
Chlorinated lime 181, 262 
Chloroform 279, 442 
Chlorophyll 343 
Chondrus 374 
Chopping 430 
Chromates 270 
Chrysophan 351, 366 
Chrysophanic acid 351 
Cirn cifuga 347 
Cinchona 355, 356 
Cinchonidine 356 
Cinchonine 356 
Cinnabar 208 
Cinnamic acid 383 
Cinnamon 356 

Circulatory displacement 438 
Cissampeline 350 
Citrates 274, 275 
Citric acid, 284 
Clarification of liquids 450 
Classes of compounds 234 
Cleavage 23 
Clouds 98 
Cloves 362 

Clusters of atoms 228 
Coagulation 338 
Coal 191 
Coca 364 
Cocaine 364 
Coction 470 
Codeine 377 
Cod liver oil 386 
Co-efficients of expansion 87 
Cohesion 12, 14, 17, 130 
Cohosh, black 347 
Colation 447 
Colature448 
Colchicine 347, 371 
Colchicum root 347 

seed 371 
Cold 73 

Collection of plant drugs 328 
Collunaria 494 
Collyria 494 
Colocynth 368 
Colocynth in 369 
Collodions 494 
Colloids 42, 43 
Colophony 3S1 
Colloxylin 494 
Color 100 

Coloring matters 343 
Colors, complementary 100 

of elements 165 

prismati 100 
Columbo347 

Combination by volume 148 
Combining power 1 3, 123-125 

proportions 139-143 

value 150, 223 

volumes 145. 146 
Combustion 76, 171,301 
Comminution 430 
Compass 103 
•Complementary colors 100 



Compound matter 115. 116 

molecules lio, lid, 224, 226 

radicals 124, 125, 213, 214, 215 

solution 439 
Compounds 115,116, 139, 234 

binary 234 

chemicals 115, 116 

classes 234 

inorganic 234 

insoluble 298, 299, 307, 308 

organic 235 

physical properties of, 168, 169 

quaternary 234 

ternary 234 

v -latile 300 
Compressibility 7 
Condensers 96, '455, 456 
Confections 478 
Conductivity of elements 166 
Conductors of electricity 104 

heH 83 
Congealing points 75, 90, 91 
Confine 369 
Conium 369 

Conservation of energy 14 
Conserves 478 
Conspergatives 479 
Constituents of drugs 332, 333 
Constitutional formulas 231 
Contraction bv coid 87 
Convolvulin349 
Copaiba 384 

emulsion 483 
Copper and compounds 207, 208 
Coriander 369 
Cornutine 374 
Correlation of energv 14 
Corrosive sublimate 140, 2C8, 241 
Cotton-root bark 357 
Cottonseed oil 385 
Cream of tartar 198, 273 
Crocus 362 
Croton oil 339, 386 
Crushing drugs 431 
Crystal, quartz 30 
Crystallic bodies 15, 19 
Crystalline bodies 15, 19 

form 15, 19, 24, 25, 28, 462 
Crystallizable substances 19, 165 
Crystallization 24, 25, 460, 461, 463, 464 

water of , 15 
Crystallizers 46 1 
Crystallography 28-34 
Crystalloids 42, 43 
Crystals 15, 18. 28 

angles of 18, 22 

anhvdrous 25 

axes 22, 23, 28 

classification of 28 

cleavage 23 

development of 463 

directions for extension of, 21, 22 

drying of, 464 

faces 18, 22, 23 

forms of 22-24, 28 

growth of 21, 25, 461, 462 

hemihedral 23 

holohedral 23 

hydrous 26 

nursing of 462, 463 



INDEX. 



I I 



Crystals production of 25, 461 463 
size of 4b i, 462 
systems of 28-34 

Assymraetric 34 

Clinometric 28 

Cubic 29 

Dimetric 31 

Doubly oblique prismatic 34 

Monoclinic 33 

Monometric 29 

Monosymmetric 33 

Oblique prismatic 33 

Orttaometric 28 

Prismatic 31 

Pyramidal 31 

Quadratic 31 

Regular 29 

Khombic 32 

Rhombohedral 30 

Right prismatic 32 

Square 31 

Tessular 29 

Tetragonal 31 

Triclinic 34 

Trimetric 32 
Cube 24, 29, 34 
Cubeb 369 
Cubebin 369 
Cubes 34 
Cubical crystals 24 

expansion 87 
Cub-c-centimeter 504, 505, 506 
Culvers' root 350 
Cupric copper 207 
Cuprous copper 207 
Cutch 375 
Cutting drugs 430 
Current electricity 105 
Cyanides 246 247 
Cyanogen 1S5, 217 
Cydonium 372 

Dalton's at©mic theory 142, 143 

law of multiple proportions 143 
Dandelion 353 
Daphnin 358 

Decantation 39, 312, 448, 449 
*'Deci-"292 
Decigram 5C4 
Declensions, Latin 496-503 
Decoction 470 

vessel 469 
Decoctions 486 
Decolorization 45 
Decomposition 5, 119, 127, 128 

double 127, 307-340 
Decrepitation 325 
Deflagration 428 
"Deka-" 29; 
Deliquescence 15 
Demulcents 397 
Density 3, 10, 11, 12 

of elements 165 

of water 88, 89 

vapor 146 
Deodorization 450 
Derivatives 234 
Desiccation 428 
Destructive distillation 429 
Dew 98 



Dew point 97 
Dextrin 335 
•'Di-' 1 292 

Diamagnetic bodies 1C4 
Diamond 19, 191 
Dialyser 43 
Dialysis 43, 470 
Diaphoretics c"96 
Diatomic molecules 147, 224 
Diffusion of liquids 41, 471 
Dige.-tants 393 
Digestion 469, 473 
Digitalis 364 
Digitoxin 364 
Dimorphous bodies 19 
Direct union of atoms 227 
Dishes 451, 452 
Disinfectants 397 
Disintegration 430 
Dispensatories 325 
Dispensing 326 
Displacement 471 

circulatory 438 
Distillate 453. 460 
Distillation 96, 453-457 

chemical 457 

dry 429 

fractional 454. 457 
Distilling apparatus 453, 454 
Divisibility of matter 4, 45, 141, 142 
Dodekahedron 29 
Dome condensers 456 
Dose table c99-418 
Doses 327, 39 i 
Double decomposition 127, 225, 297—300, 

307— 310 
Double sallte 258 
Draft 84 

Drastic purgatives 396 
Drug mills 84 

structure 334 
Drugs 317, 320, 322 

acrid 343 

animal 318, 391 

annual supplies of 328, 329 

collection of 328 

constituents of 332 

crude 317, 320-32^ 

definitions 330 

desiccation 331, 332 

fibrous 334 

grades 321 

identification 320 

inorganic 317 

organic 317 

preservation of 328, 332 

tissues of 334 

varieties 321 
Drum seives 436 
Dry distillation 429 
Drv processes 130, 131 
Dry way 130, 11 
Ductilitv 7, 163 

Dulong and Petit, law of 143, 144 
Duo 292 
Dyads 152, 153 

Dynamic electricity 102, 105 
Dynamics 13, 47 

Ebullition 94, 451 



5 12 



INDEX. 



Edges of crystals 18 
Efflorescence 15, 26 
Elasopten 341 
Elasticity 7, 16 
Elder flowers 363 
Electric batteries 105 
cells 105 
circuit 105 
currents 105 
phenomena 104 
plates 105 

polarity 103, 105, 134, 136 
Electricity 13, 102, 129 

conductors of 104 

dynamic 102, i05 

frictional 10. 

galvanic 102, 134 

negative 103, 134 

positive 103, 134 

static 102 

voltaic 102, 134 
Electricity, relation to chemistry 125, 

133, 134, 2i4 
Electro-chemical polarity 125, 135, 214 

series 136-138 

theory 135 
Electrodes 105 
Electrolysis 106, 134, 135 
Electrolytes 106, 134 
Electro-negative radicals 135 
Electro-plating 106 
Electro-positive radicals 135 
Electro-typing 106 
Electuaries 478 
Elements 112, 113, 14 

electro-negative 136 

electro-positive ]38 

metallic 16 <, 211-213 

non-metallic 163, 164, 195 

chemical behavior 168, 169 

occurrence in nature 166 

physical properties 164-169 

polyvalent 138 

proportions of, in compounds 139-143 

review of 163 

symbols of 162 

table of 112-113 
Elutriation 434 
Emetics 395 
Emetine 349 
Emmenagogues 395 
Emodin 351, 357 
Emollients 397 
Empirical formulas 2S0 
Emplastra492 
Emulsification 482,483 
Emulsifying agents 482, 483 
Emulsion 338, 358, 482 
Emulsion mortar 432 

of turpentine, 433 
Emulsions 482, 483 
Endings 496-503 
Enemata 494 
Energy i3 

chemical 113, 123-125 

conservation of, 14 

correlation of, 14 

electrical 102 

kiaetic 74 

of motion 53, 74 



Energy of position 53, 74 

potential 74 

radiant 85 
Ennea 292 
Epsom salt 203 
Equations, chemical 161, 162 
Equilibrium 50 
Equivalence 151 
Equivalent radicals 153 
Ergot 374 
Ericolin 367 
Erythroxylon 364 
Escharotics 397 
Eserine 373 
Essential oils 340 
Esthers 285 
Ether as a solvent 442 
Etherial oils 340 

salts 285 
Ethers 284, 286 

compound 285 

simple 284 
Ethyl 217 
Eucalyptus 365 
Eupatorium 360 
Evaporating dishes 452 
Evaporation 93, 95, 451, 452, 453 

cold from 95 

rate of 93 

spontaneous 93 
Excess of one factor in 310 
Excipients 479 
Expansibility 7 
Expansion, co-efficients of 87 

cubical 87 

force of 87 

linear 87 

in solidification 91 

of bodies by heat 86 

of water 88, 89 

unequal 88 
Expectorants 396 
Exsiccation 428 
Extract 467, 488 
Extraction 467 

forces concerned in, 470 

methods 468 
Extractive 467, 468 
Extracts 488 



Fats 333, 338, 339, 385 

animal 339 
Fatty series 279 
Faces of crystals 18 
Factors of reactions 125, 126, 305, 

310 
Fahrenheit's thermometer 78 
Fel bovis 391 
Fennel 370 

Fermentation 122, 337, 450 
Ferric compounds 206 

iron 205 
Ferrous compounds 206 

iron 205 
Fibrous drugs 334 
Filter baskets 447 

funnels. 445 446 

paper 444 

stands 446 



INDEX. 



513 



Filters 443-445 

plain 144 

paired 445 
Fi trate 443 
Filtration 443-447 
Fineness of powders 436 
Fire 129 
Fixed alkalies 91. 131 

substances 18, 91 

oils c 33, 3o8, 339, 385 
Flasr. blue 349 
Flasks 454. 4^9 
F. ax seed 372 

oil 385 
Flowers 331. 332 

of sulphur 177 
Fluids j 7 

Fluid-extracts 487 
Fluorescence 101 
Foeniculum 370 
Fog 98 

Foot-pound 54 
Force 8 

centrifugal 49 

chemical 113, 153, 124 

constant 52 

electric 102 

of expansion and contraction 87 

repellant 12^ 

attractive 8-12 
Forces 8 
Formic acid 282 
Formulas, chemical 159, 160, 219, 230,231, 

276, 27^. 285 

constitutional 231 

empirical 230 

for acids 219 

general 276, 277, 278. 285 

molecular 159, 160, 230 

rational 231 

structural 231 

symbolic 159, 160 
Foxglove 364 

Fractional distillation 454, 457 
Frangula 357 
Frangulin 357 
Franklinism 102 
Freezing by evaporation 96 

mixtures 92 

points 9('. 91 

solutions to concentrate them, 46 
Friction 58 

Frictional electricity 102 
Frost 98 
Fruit acids 340 
Fruit flavors, artificial 285 
Fruits 332 
Fuel! 73, 422,423 
Fulcrum o5 
Funnels 445, 446. 447 
Fusel oil 281 

Fusibility of elements 164 
Fusing points 75, 90 
Fusion 90, 428 

aqueous 129 

igneous 129 

Calbanum 380 

Galen 319 

Galenical preparations 319 



Galena 19, 206 

Galla 359 

Gallic acid 359 

Galvani 133. 134 

Galvanic electricity 102, 134 

Gamboge 380 

Gargles 494 

Garlic 345 

Gas burners 424, 455 

liquor 2U0 
Gases 17, 6ti, 87. 90, 96 

atoms of in equal volumes 145 

expansion of 87 

generation and solution of 458 

tension of 66 
Gelsemine 348 
Gelsemium bi~ 
Genitives. Latin 496-5C0 
Gentian 348 
•'Gentle heat" 457 
Ginger 354 
Glass 194, 270 

Glass tuhinff. cutting of 459 
Glauber's salt 199 
Glucose 288, 335. 337, 379 
Glucosides *88, i95. 343 
Glycerin 28-. 338, 442 

bath 427 
Glvcerites48i 
Glyceryl 217, r38 

saits 338, • 39 
Glycogelatin 494 
Glycvrrhiza348 
Glycyrrhizin 34S 
Gold 210 
Golden seal 348 
Gossypii radicis cortex 357 
Guaiac resin SSL 

wood 354 
Guarana 375 
Guaranine 376 
Gum arabic 335. 378 

properties of 335 
Gums 333, 335, 3: 6 
Gum-resins 342. £43 

emulsions of 4^2 
Gun-cotton 404 
Gram 501. 505, 0C6 
Granatum 357 
Granulation 464 
Granules 478. 479 
Grape sugar L37 
Graphite 191 
Grating of drugs 431 
Gravity 9 
Gravitation 9 
Grindelia 360 
Grinding drugs 431 

Ha?matoxvlon 355 

Hail 98 

Halogens 179. 240 

Haloids 176, 240-252, 253, 258 

Hardness 7 

Hartshorn salt 200 

Hellebore, American 354 

Hemlock 369 

Hepta 292 

Heptads 152, 153 

Herbs 331 



5i4 



INDEX. 



Hesperidin 355 

Heterogeneous bodies 36, 11^, 116, 120 

Heteromorphous bodies 20 

Hexa 292 

Hexads 152, 153 

Hexatomic molecules 148, 224 

Heat 13, 73, 74, 75 

absolute 80 

absorption 86 

active 74 

action of upon salts 129 

amount from fuel 422 

and chemism 128, 129 

a repellant force 128 

atomic 144 

conduction 82, 83 

conductors 83 

control of 425 

convection 82-84 

distribution 82, 425 

effects of 421 

expansion 86 

intensity 101, 422 

in pharmacy 421 

latent 74, 92, 95, 96 
of vapors 95 

molecular 145 

non-conductors of 83 

radiant 85. 98 

radiation 82, 84, 8j 

reflection 85 

refraction 85 

sensible 74 

softening by. 91 

sources of, 76 

specific 80, 81, 82 

theories of, 73, 75, 85 

transmission of, 85, 86 

unduiatory theory of 85 

units 81 

waves 85 
Heating apparatus 423 
Hippocrates' sleeve 448 
Hoarhound c61 

Homogeneous masses 37, 110, 115 
Homologous series 234, 277, 278 
Honey, 337, 379 
Honeys 481 
Hops 370 
Horse-pQwer 54 
Hot- water coil 424 
Humulus 370 
Hydracids ;53 
H ydragogue cathartics 396 
Hydrastine 348 
Hydrastis 348 
Hydrates 2 12, 215, 248, 249 
Hydraulic press 60 
Hydriodic acid 182 
Hydrobromic acid 182 
Hydrocarbons 276-280 

of methane series 286 

nomenclature of 295 
Hydrocarbon radicals 279, 180 
Hydrochloric acid 140, 181,254 
Hydrocyanic acid 185 
Hydrodynamics 58 
Hydrogen 173 

acids 176. 253 

alloys 175 



Hydrogen arsenide 189 

as a reducing agent 173 

bromide 182 

chloride 18L 

nascent 130 

negative 176 

peroxide 174, 215 

polarity of 138, 175 

positive 176 

radicals 176 

replaceable 175, 176, 219 
Hydrogen solidified, 175 

sulphide 179 

valence 151 

variable polarity 175 
Hydromel 481 
Hydrometers 63-66 
Hydrostatic balance 55, 63 

paradox 59 

press 60 
Hydrosulphuric acid 178 
Hydrous crystals 26 
Hydroxides 215, 247-2j;0 
Hydroxyl 138, 174, 175, 215-217, 247, 282 

acids 172, 2:51, 252 
table 25 i 
Hygroscopic bodies 15 
Hyoscine 365 

Hyoscyamine346, 363, 365, 366, 373 
Hyoscvamus 365 
Hyper- 294 
Hypnotics 395 
Hypo- 294 

Hypochlorites 181, 262 
Hypophosphites267, 268 
Hyposulphites 264 

Iceland spar 19 

"ic" 292-295 

Identification of drugs 320 

Igneous fusion 129 

Ignition 428 

Impenetrability 2, 6 

Imperial weights and measures £04, CC5 

Incandescence 99 

Incineration 428 

Inclined plane 57 

Incompatibilities 299 

Indeclinable nouns 498 

Indestructibility 6, 118, 119 

Indian cannabis 360 

hemp 360 

tobacco 360 
Induction 103 
Inertia 7, 48 
Infusion 469, 470 
Infusions 484 
Ingredients 36 
Injections 494 
Inorganic chemistry 168 

compounds 234 

drugs 317 

substances 109 
Insoluble compounds 29S, 299, 307, 3CS, 44i 
Insulators 104 
Iodides 244, 245, 246 
Iodine 182 
Iodoform 279 
Ipecac 349 
Iris versicolor 349 



INDEX. 



5*5 



Irish moss 374 
Iron 205, 206 

group 204 
Irritants 397 
Isomorphous bodies 20 

J aborandi 365 
Jalap 349 

Jasmine, yellow 347 
Javelle water 262 
Jervine 354 
Jimpson weed 366 
Juniper 370 

Kamala 370 
Kermes mineral 238 
Ketones 282 
Kilogram 502, , r 03. 504 
Kilogram meter 54 
Kilometer 504 
Kinetic energy 53 
Kino 376 
Koosso 361 
Krameria 349 

Labarraque's solution 181, 263 

Laboratory thermometers 79 

Lactates 272 

Lactic acid 283 

Lactucarium 376 

Lamp stand 446 

Lard 385 

Lard oil 385 

Latent heat 92, 95, 96 

Latin declensions 495-502 

names 495, 496 
Laughing gas 183 
Lavender 362 
Law of Archimedes 61-66 

Avogadro 146, 147 

Boyle 87 

Charles 67, 80, 87 

combining proportions 140-143 

Dalton 140-14'% 

Dulong and Petit 143, 144 

gravitation 9 

Mariotte 66, 87 

opposites in chemistry 131-136 
Laws of motion 48 
Laxatives 396 
Lead and compounds 206, 207 

plaster 493 
Leaves 331, 332 
Leptandra3 
Levers 55, 56 
I.evigation 434 
Licorice root 348 
Liehig's c ndenser 455 
Light, 13, 98 

absorption of, 100 

chemical effects of, 101 
rays of, 101 

effects of, upon drugs, 101, 102 

heat rays of, 101 

luminous, rays of, 101 

radiation of, 99 

ravs 99, 100, 101 

reflected 100 

refraction of, 100 

sources of, 99 



Light, white. 99 
Liguin 333, 334 
Lime 20 L 

water 201, 248 
Line of direction 50 
Linear expansion 87 
Liniments 494 
Linkage 229 
Linseed Oil 385 
Linum 372 
Liquids 16, 90 

decantation of 39 

diffusion of 41, 471 

form of 21 

miscible 36, 4R, 47 

pressure of 58, 59 

viscous 447 

volatile 92. 93 
Liquores 441, 480 
Liquorice root 348 
Liter 1 03, 504. £05 
Lithium 199 
Litmus paper 303 
Liver of sulphur 238 
Lobelia 360 
Lode stone 102, 103 
Logwood 355 
Lotions 494 
Lozenges 478 
Luminous bodies 99 

rays 99 
Lupuiin 370 
Lustre of elements 165 

Macera+ion 468, 473 

Machine o5 

Magdeburg spheres 73 

Magma 312 

Magnesia 203 

Magnesium and compounds 203 

Magistral formulas 324 

Magnetic substances 103 

Magnetism 102 

Magnets 102, 103 

Malaguti's law %96-298 

Male fern 346 

Malic acid 284 

Malleability 7, 166 

Mandrake 350 

Manganese chlorides 141 

dioxide 171 

oxides 140, 142 
Manna 337, 379 
Man nit 379 
Maple sugar 336 
Maranta 378 
Marble 201 
Marc 475 
Mariotte's law 66 
Marrubium 361 
Marsh gas 276, 279 
Marshmallow 3i6 
Mastic 382 
Mass 2, 6 

attraction 8-12 

motion 13 
Masses 114, 478 

heterogeneous 10 

homogeneous 110 

molecules and atoms L16, 117 



5i6 



INDEX. 



Massing 479 

mortars 433 
Materia medica 319 

pharmaceutica 320 
Matico 365 
Matricaria 363 
Matter 2 

atomic 6 

divisibility of 141, 142 

frozen 90 

kiods of 5, 115 

melted 90 

molar 6 

molecular 6 

properties 4-8 

states of aggregation of 14 

vaporized 9U 
Maximum density of water 8?, 89 

solubility 438 
Measures 503-505 
Mechanical science 13 
Medicines 317 

systemic 392 

topical 392 
Mel 379 
Mellita 481 
Melting points 75, 90 
Mendeleef 's periodic law 169, 170, 210 

table 170 
Menstrua 442 
Mentha piperita 361 
Menthol 389, 391 
Mercaptans 282 
Mercur-ammonium 217 
Mercurial thermometer 77 
Mercuric mercury 207 
Mercurous mercury 207 
Mercury and compounds 207, 208, 209 
"Meta"294 

Metallic compounds 213 
Metals 163 

action of acids on, 254, 255 

alkali 196, 197 

alkaline earth 200 

chemical behavior of, 168 

heavy 196, 204 

light 196 

noble 210 

polarity 136 

relative power as positive radicals 
136, 138 

review of, summary 211-213 
Metaphosphates 267 
Meter 503, 504 
Methane *76, 279 
Methene 217 
Methenyl 217 
Methyl 217 

salicylate 388 
Metric system 503 

units, equivalents of 504 
Mezereum 357 
Microcrystalline bodies 21 
Milk sugar 337 379 
Milligram 503,504 
Mineral kingdom, 109 

substances 109 

tonics 393 
Miscibility 36, 46, 47 



Mitscberlisch's condenser 456 

definition of isomorphism 
Mixed substances 36, 37, 1 10, 1.6 
Mixtures 36, 37, 111), 116, 482 
Mixture mortars 433, 431 
Mobile liquids 16 
Molar attraction 8, 12 

force 13 

matter 6 

motion 13 
Momentum 49 
Mon-acid bases 249 
Monads 152, 153 
Monatomic molecules 224 
" Mono-" 292 
Monobasic acids 251 
Morphine 376, 377 
Morphology 323 
Mortar, iron 431 
Mortars 431-434 
Moschus 392 
Mother liquor 309. 464 
Motion 13, 47 

laws of 48 
Motor depressants 394 

excitants 394 
Molecular attra- tion 8, 12 

formulas 159, 160, 230, 233 

heat 145 

matter 6 

motion 13 

weight 145-148 
Molecules 5, 6, 114, 116, 117 

atomicity of 147, 2-4 

complex 157 

compound 114, 224, 2^6 

diameter of 142 

diatomic 147 

elemental 114 

formation of 225, 2^6 

hexatomic 148 

number of in volumes cf gases 147 
atoms in 147 

sta.bl6 129 

stability of, relative, 123, 129, 131, 136 

tetratomic 147 

triatomic 147 

unstable 129 
Mucilages 333, 335, 336, 481 
Mucilaginous drugs 3.5 
" Multi -" 294 

Multiple proportions 140-143 
Muriate of ammonia 200 
Muriatic acid 181, 132, 133 
Musk 392 
Mustard 373 
Mydriatic anodynes 394 
Myristica 372 
Myrrh 381 

Names of compounds 289-295 
Nascent state 130 
Natural gas *79 
Negative pole 134 

radicals 135, 136, 215, 217, 222, 223 
Neumann's investigations 1 44 
Neutral principles 288, 295, 3_3, 343 
Neutralization 132, 303 
Nicholson's hydrometer 61 
Nicotine 367 



INDEX 



517 






Nitrates 213, 259-261 

Nitre 260 

Nitric acid 133, 183, 185, 254, 301 

anhydride 235 

radical 259 
Nitrogen 183 

group 182, 186 

compounds of 187, 195 

indifferent energy 184 

negative 154 

oxides 141, 183, 184 

poly valence of 184 

positive 154 

radicals 184 

valence of 154 
Nitrosyl 217 
Nitrum 132 
Nitryl 217 
Nomenclature 289, 295, 324, 495 

chemical 289, 295 

Latinic 495 
Nona 292 

Numerals, use of, 159, 292, 500 
Nutgall 359 
Nutmeg 372 
Nux vomica 372 

Oak bark 358 
Octo 292 
Octohedron 29 
Official 324 
Officinal 324 
Officine 324 
Oil bath 4*7 
castor 339 
croton 339 
emulsions 483 
of allspice 389 

almond 385 

anise 387 

bergamot 387 

bitter almond 387 

caraway 387 

cinnamon 388 

cloves 388 

copaiba 388 

coriander 388 

cubeb 388 

eucalyptus 388 

fennel 388 

juniper 389 

lavendeo- 389 
flowers 389 

lemon 389 

mustard, volatile 390 

neroli 387 

orange flowers 387 

orange peel 387 

peppermint 389 

pimenta 390 

rose 390 

rosemary 390 

sassafras 390 

savin 390 

star anise 387 

theobroma 386, 493 

turpentine 390 

vitriol 132, 133 

wintergreen 388 
Oil, olive 338, 386 



Oils, drying 339 

esseutial &33, 340, 341, 387 
ethereal 340, 387 
fixed 333, 338, 339, 385 
non-drying 339 
volatile 333, 340, 341, 387 
Ointments 491 
Oldberg's percolator 471 
uleates, 272, 338, 493 
Oleoresins 342, 490 
Oleum adipis 385 

amygd. amar. 387 
express. 385 

anisi 387 

aurantii cort. 387 
flor. 387 

bergamii 387 

cari 387 

caryophylli 388 

cinnamomi 388 

copaibas 388 

coriandri 388 

cubebas 388 

eucalypti 388 

fceniculi388 

gaultheriae 388 

gossypii 385 

juniperi 389 

lavand. 389 
flor. 38 

limonis 389 

lini 385 

mentha? pip. 389 

morrhuae 386 

olivge 386 

pimenta? 389 

ricmi386 

rosse 389 

rosmarini 390 

sabinae 390 

sa saf ras 390 

sesami 386 

sinapis vol. 390 

terebinth. 390 

tiglii 386 

theobromae 386, 493 
Oleic acid 339 
Olein 338 
Olive oil 338, 386 
Opacity of elements 165 
Opaque bodies 99, 165 
Opium 376 

Opposites in chemistry 131-136 
Orange peel 355 
Ordinals 501, 502 
Organic acids 282-284, 333, 340 

bodies, forms of 21 

chemistry 192 

compounds 235 

drugs 317, 320-322 

oxides 284 

substances 109 
Organized matter 21 
Organography 323 
"Ortho— " 294 

Orthometric forms of crystals 28 
Orthophosphates 265—266 
Orthosulphuric acid 275 
Osmose 42, 470 
Otto 340 



5i« 



INDEX. 



"-ous' 1 29?-295 

Ox-gall 391 

Oxalates 273 

Oxalic acid 283 

Oxidation 171. 259, 3 1, 302, 428 

Oxides 133. 172, 212, 235-237 

table of 236-237 

acid-forming 138, 235 

basic 138, 235 

higher and lower 293 

indifferent 235 

neutral 235 

nomenclature of 291-293 

organic 284 

of chlorine 141, 180 

hydrocarbon radicals 284 
manganese 140 
nitrogeDl41,183, 184 
sulphur 178 
Oxidizing agents 259, 3C2 
Oxygen 171, 2il 

compounds 177 

electro- chemical polarity of 138 

radicals 173 
Oxy-chlorides 240 
Oxv-hydrogen burner 173 
Oxy-oleic acid 339 
Oxv-salts 172,215.258 
Oxy-sulpburet of antimony 2, 33 
Oxymel 481 
Oxytocics 395 
Ozone 172 



Palmitin 339 
Palmitic acid S39 
Paper filters 444 
Papers, medicated 491 
Papin's digester 94 
Para- 294 
Paraffin 279 
Paregoric 377 
Pareira 350 
Pearl ssh 199 
Pectin 333, 336 
Pelletierin 3 7 
Pendulum 52, 53 
Penta- 292 
Pentads 152, 153 
Pentatomic molecules 224 
Pepper, African 367 

black 371 

Cayenne 367 

red 367 
Peppermint 361 
Pepsin 392 
Per- 294 
Percolate 471, 474 

weak 474 
Percolation 471-475 

simple 474 
Percolators 471, 472 
Periodic function of atomic weights 

law 169 
Perissads 152 
Permanganate 270 
Peruvian bark 356 
Peroxide of hydrogen 174 
Pharmaca praeparanda 320 

simplicia 320 



Pharmaceutical chemistry 318 

preparations 319 
Pharmaco-dynamics 326 
. Pharmacognosy 320 
Pharmacology 320 
Pharmacopoeia 324, 325 
Pharmdco-technologv 326 
Pharmacy 325, 326, 4=h 
Phenolsulphonates 275 
Phenomena 8 

chemical 118-123 
Phenyl 217 

Phosphates 212, 265, 266 
Phosphine 188 
Phosphorescence 99 
Phosphorus 186, 187 

acids of, 188 

compounds 187, 188 

negative 154 

oxides 187 

positive 154 

red 187 

valence 154 
Phosphoric acid 1S8 

anhydride 235 
Physical properties of matter 117, 120 

science 1)8 
Phvsics 117. 118 
Physiology 327, 328 
Physostigma 372 
Phytolacca 350 
Pill mortars 433 
Pills 4T8, 479 
Pilocarpine 365 
Pilocarpus 365 
Pinkroot 353 
Piper 371 
Piperine 371 
Pipettes 69 
Pix burgundica 382 

liquida 384 
Plant constituents 332 

drugs 328 
Plaster of paris 2^1 
Plasters 272, 339, 492 
Platinum group 210 
Pneumatic inkstand 69 
Pneumatics 58, 66 
Podophyllin 351 
Podophyllum 350 
Poisons 3.8 
Poke root 350 
Polar force 103 
Polarity and valence, 154, 155 

electro-chemical 125, 135, 154, 155, 214 

relation of to atomic weight 13i 
valence 138 
Poles of the magnet 103 

opposite 103 
Poly- 294 

Polyatomic molecules 224 
Polygalic acid 352 
Polymorphous bodies 20 
Polyvalent elements 138, 182, 186, 192, 193 

nerissads 182, 186 

radicals 15 J 
Pomegranate root bark 357 
Porosity 6 
Positive pole 134 

radicals 135, 215, 217, 220-222 



INDEX. 



519 



Posology 327 

Potential energy 53 

Potassium and compounds 198, 199 

position of in electro-chemical se- 
ries 138 
Potassa 248 
Poultices 491 
Powder mixing 433 

mortars 432 
Powders 43ft, 436, 437, 477 
Precipitate 306 
Precipitates 311 

drying 313 

properties 466 

washing 311, 312 
Precipitating vessels 308, 466 
Precipitation 46, 298, 299, 306, 307, 465, 466 

chemical 307 

physical 46, 307 
Precipitand 308 
Precipitant 308 
Predisposing affinity 131, 183 
Prefixes in nomenclature 290-294 
Preparations 3i9, 476, 477 

class fication 476, 477 

extemporaneous 324 

galenical 219 
Press, Brahmas 60 

hydraulic 60 

hydrostatic 60 
Pressure, relation of to boiling points 94 
Primary colors 100 
Principles, active 333 

inert 333 

neutral 333, 343 

proximate 332 
Prism, rhombic 33 
Prismatic colors 100 
Prisms 24, 30-34 

hexagonal, 30 

monoclinic33 

quadratic 32 

six-sided, 30 

tn-clinic30 
Processes, dry, 130, 131 

wet. 130, 131 
Products of reactions 309, 125, 126 

principal 309 

secondary 309 
Properties chemical 118 

physical 170, J 20 
Propo' tions combining 139-143 

multiple 140-1 3 

of factors in reactions 309, 310 

volume 145, 148 
Protiodide of mercury 245 
Proto 294 

Proximate principles of drugs 332 
Prunin 358 

Prunus virginiana 358 
Prussian blue 26, 246 
Prussic acid 185, 246 
Pulley 57 
Purgatives 396 
Putrefaction IJ38 
Pyramid, hexagonal 30 

monoclinic 33 

rhombic 33 

square-based 32 

triclinic 34 



Pyramids 24, 30, 32, 33, 34, 35 
Pyrites 177 
Pyro .94 

Pyroarsenates 270 
Pyrocatechin 384 
Pyroleum 384 
Pyromerers 79 
Pyrophosphates 2 
Pyroxylin 494 

Quadri 294 

Quadrivalent radicals 152, 153 

Quantity of chemism 150 

Quativalence 151 

Quartz cr} stal 30 

Quassia 355 

Quaternary compounds 234 

Quebracho 355 

Queen's root 353 

Quercitaunic acid 358 

Quercus alba 358 

Quince seed 372 

Quinidine356 

Q -inine356 

Quinque 292 

Quinquivalent radicals 152, 153 

Radiation of light 99 
Radicals 124, 125 

acid 251, 253 

acid -forming 216, 253 

acidulous 222, 223 

basylous 220, 221,223 

compound 124, 125, 213, 214, 215 

elemental 124, 125 

how united 226 

hydrocarbon 286 

negative 135, 215, 217, 22?, 223 

nomenclature of 215 

of the methyl series 283 

organic 285 

positive 135, 136, 176, 215, 217, 220, 
221, 21 12 

relative energy of 296 

salt 256 

simple, 124, 125 

tables of 220-223 

valence of 151, 220-223 
Rain 70 
Kancidity 339 
Rasping of drugs 431 
Rational formulas 231 
Rays of light 99 
Reaction on test paper 303-305 
Reactions, 119-123, 12,-131, 225, 253, 255, 

296-300,305,3,6,309, 310 

analytical, 126 

between dry substances 127, 128 
gases 127 
liquids, 128 

direction and completeness of 296- 
300 

factors of 125, 1 6 

proportions of 309, 310 

laws governing, 296-300 
of acids and bases 253 

with metals, oxides, etc. 255 
on litmus paper 303-305 
products of 125, 126 



5 



Reactions, synthetical 126 
Reagents 126 

Reaumour's thermometer 78 
Receivers 96, 456 
Red pepper 203 
Red precipitate 367 
Reducing asrents 173, 264, 302 
Reduction 302. 428 
Reflection of heat 85 

light 100 
Refractory bodies 90 
Ret -angibilirv of beat rays 85 

light i00. 10 L 
Regnault's investigations 144 
Re-maceration 468 
Repeilant force 81, i:8 
Repercolation 474 
Replacement 333 
Repulsion 8 
Residue 219, 249, 251 

acid 251 

base 249 
Resin s aps 343 
Resina 381 
Resinification 341 
Resins 333, 341,342 

acrid 342^ 

balsamic 342 

hard 342 

precipitated 490 

soft 342 
Resistance 51 
Retorts 454 
" Retort stands " 446 
Rhamnus purshiana 358 
Rhatany 349 
Rheum 351 
Rhizomes 331 
Rhombohedron 31 
Rhubarb 351 
Rings 229 
Roasting 428 
Rochelle salt 199 
Rock candy 337 

crystal 19 
Roman numerals 500 
Roots 331 
Rose 362 
Rosemary 366 
Rosmarinus 366 
Rottlerin 370 
Rubefacients 397 
Rubus 359 
Rust 122 

Saccharose 288, 336, 378 

group 288 
Saccharum 378 

lactis379 
Saffron 362 
Sa*e3d6 
Sal ammoniac 200 

soda? 199 

volatile 200 
Salicylates 275 
Saline cathartics 396 
Salt 240 
Salt formers 172, 179. 180 

of tartar 199 

radicals 256 



INDEX. 



Saltpetre 199. 260 
Salts 172, 256-258 

acid 256 

action upon, by heat 129 

alkaloidal 289 

basic 257 

classes of 256, 257 

double 25^ 

nomenclature 291, 295 

normal 256 

of alkaloids 289 

reactions of, on litmus paper 303- 
305 
Salvia 366 
Sambucus 363 
Sand bath 42b 
Sanguinaria 351 
Santonica 363 
Santonin 363 
Saponin 352 
Sarsaparilla 351 
Sassafras 359 

Saturating power of atoms 150 
Saturation 132, 305 
Scale salts 206 
Scalenohedron 31 
Scammony 382 
Scilla 352 
Sclererythrin 374 
Scleromucin 374 
Sclerotic acid 374 
Screw 57 

Secale cornutum 274 
Seconds pendulum 53 
Sedatives 395 
Sediment 450, 465 
Seed emulsions 482 
Seeds 332 
Selenium 178 
Semi-fluids 16 
Semi-sol ; ds 16 
Senega 352 

Seneka— «nakeroot 352 
Senna 366 

Septivalent radicals 152. 153 
Sexivalent radicals 152, 153 
Serpen taria 352 
Sesamum oil 386 
Sesqui- 294 
Sevum 3^5 
Sexi- 292 
Sieves 43 \ 436 
Silicates 269, 270 
Silicon 194 

Silver and compounds 219 
Simple solvents 440, 441 
Sinapis 373 
Siphons 70, 71,449 
Skeletons 228 
Slicing drugs 430 
Slippery elm bark 359 
Snake-root 347, 352 
Snow 98 
Soaps 272. 338, 339, 342 

resin 342 
Soda 199, 248 

Sodium and compounds 199 
Solar spectrum 100 
Solids 14, 15, 90 

form of 15 



INDEX. 



521 



Solubility 44, 440-442 

maximum 438 

of elements 166 
Solution 44, 437-443 

baths 94, 427 

chemical 45, 439 

compound 45, 439 

fractional 440 

of gases 440, 460 

liquids 440 

soJids 437 

partial 439 

saturated 45, 439 

simple 45 

super-saturated 439 
Solutions 441, 480 

boiliDg points of 94, 427 

concentrated by freezing 46 

of gases 460 
SolveDts, 44, 46, 440, 441, 442 

chemical 46 

neutral 46 

simple 40 

pharmaceutical 440-442 
Sorghum sugar 336 
Sound 13 
Spanish flies 391 
Spatula 434 
Species 430, 477 
Specific gravity 10, 12, 146 

heat 143, 144 

weiarht 10, 1-', 146 
Spectrum 100 
Spermaceti 385 
Spices 342 
Spigelia353 
Spiral condensers 456 
Spirit lamp 424, 4i5 

of hartshorn 200 
Spirits 484 
Spritz bottles 71 
Squill 352 
Stability 51 
Stable molecules 129 
Stands 446 
Starch 333, 334, 378 
States of aggregation 14, 17, 
Statistical electricity 1U2 
Status nascens 130, 183 
Steam 95, 424 
Stearic acid 339 
Stearin 339 
Stearopten 341 
Sticking plaster 492 
Stillintna 353 
Stills 96, 453 
Stimulants 395 
Stinkweed 366 
Storax 383 
Straining 447 
Stramonium 366 

seed 373 
Stress 48 

Strontium and compounds 202 
Structural formulas 231 
Strychnine 372 
Styracin 383 
Styrax 383 
Styrol 383 
Sub 294 



Sublimation 90, 97, 429 
Subsidence 448 
Substances 5 

mixed 110 
Substitution 135, 225, 233, 234 

products 234 
Succinic acid 284 
Sucrose 336 
Sudorifics 396 
Suet 385 
Sugar 378 

beet 336 

grape 337 

maple 336 

milk 379 

names of, 293 

sorghum 336 

white 336 
Sugars, 333, 336-338 
Sulphates 212, 262-264 
Sulphides 212, 238, 239 
Sulphites 2-54, 265 
Sulphocarbolates 275 
Sulpho-cyanogen 217 
Sulphur 138, 176 

compounds 177 

dioxide 178 

negative 154, 177 

oxides 178 

positive 154 

trioxide 178- 

valence of 154, 177, 178 
Sulphurated antimony 238 

lime £38 

potassa 238 
Sulphuretted hydrogen 178 
Sulphuric acid 138, 178, 254, 262 

anhydride 178, 235 
Sulphurous acid 178 

anhydride 178 
Sulphuryl 218 
Sulphydric acid 178 
Super 294 

Supernatant liquid 448 
Suppositories 493 
Symbolic formulas l',9, 160 
Symbols 112, 113, 158, 162 
Synaptase 338 
Synthesis 126 
Systemic medicines 393 
Syrups 336, 481 
Sweet flag 346 
Tabacum 367 
Tablets 478 
Tannic acid 344, 359 
Tannin 344, 359 
Tar 384 

Taraxacum 353 
Tartar 198, 273 

emetic 274 
Tartaric acid 283 
Tartrates 2W, 274 
Technical terminology 495, 496 

terms 323 
Technology 326 
Tellurium 178 
Temperature 75, 77 

absolute 80 

effects of 427 

equalization of 82, 91 



5 22 



INDEX. 



Temperature of vapors 93 
Tenacity 7, 160 
Tension 17, £6, 89 
Tenaculum 448 
Ter- 292 
Terebmthina 384 

canadensis 384 
Terminology 323, 495, 4 96 
Ternary compounds 23' 
Terpenes 341 
Test papers 303 
Tetra 292 

Tetra ba^ic acids 251 
Tetrads 152, 153 
Tetratomic molecules 147, 224 
Theine 376 
Therapeutic classification of medicines 

392 
Therapeutics 3?7 
Thermal rays 85 

units 81 
Thermometer, Celsius' 77 

centigrade 77 

Fahrenheit's 78 

Reaumour's 78 
Thermometers 77—79 

air 79 

laboratory 79 

spirit 79 
Thermometric degrees 78 

scales 78 
Thermometry 77 
Thiosulphates 264 
Thistle tube 41, 455 
Tin and compounds 194 
Tincture of iron 206 
Tinctures 486, 487 
Titles 496 
Tobacco 367 

Indian 3H0 
Tolu 383 
Tonics 393 

Topical medicines 392 
Torrefaction 428 
Torricellian vacuum 72 
Toxicology 328 
Tragacanth 335, 378 
Translucent bodies 99 
Transparent bodies 99 
Tri- 292 
Triads 152, 153 

Triatomic molecules 147, 224 
Tri basic acids 251 
Trimorphous bodies 20 
Trituration 433 
Triturations 477 
Trivalent radicals 152, 153 
Troches 478 
Turpenes 341 
Turpentine 384 

Canada 384 

emulsion 483 
Tvpe theory 231, 232 
Types, chemical 232 

Ulmus359 
Cni- 292 
Units of heat 

work 54 
Univalent radicals 152, lo3 



Unstable molecules 129 
Ursone 3b7 
Uterine sedatives 395 
Uva Crsi 367 



J, 95 



Vacuum 3, 71, 7 

pans 7 A 453 
Valence 12\ 150-158, 233 

and polarity 154, 155 

the formation of molecules 
226, 2 7 

how indicated 161 

maximum 155, 156 

of chlorine 180 

nitrogen 154 

phosphorus 154 

sulphur 177, 178 

radicals 2.'0-223 

reduction of 155, 156 

relation of to polarity 138 

ruling 156 

true J 55 

variable 154-158, 290 
Valentine 3i9 
Valerates 271 
V alerian 353 
Valeric acid 353 
Vanilla 371 
Vanillin 371 
Vapor 17, 97 

density 146 
Vapors 96 

latent heat of 95,96 

specific weight of 146 

tension of 66 
Vaporizable solids 90, 91 
Vaporization 94, 45 L 
Variable valence 154-lc8 
Varnishes 342 
Vegetable kingdom 109 
Velocity 49 

accelerated 52 

of falling bodies 51, 52 
Ventilation 84 
Veratrum yiride 354 
Vesicants r97 
Vinegars 486 
Viscid liquids 16 
Viscous bodies 16, 35 

liquids 16, 35, 447 
Vitriol, blue 208 

green J.06 
Volta 133. 134 
Voltaic electricity 102, 134 
Volatile bodies 18, 90, 92, 93, 164 

elements 164 

liquids, 92, 93 

oils 333, 340, 341, 387 

products of reactions 300 

solids 90 

substances 18 
Volatilization without fusion £0 
Volume 2 

combination by 145, 148 

expansion of, by heat £6 
Volume proportions in chemical com- 
bination 145 
Volume relation of to weierht 10-12, 88„ 

89, 503, 504, 505 






INDEX. 



523 



Warmth 73 

Wash bottles 71, 458, 459 

water 312 
Washing of precipitates 311, 312 
Washings 312 
Water 13», 139, 140, 171, 173, 174 

as a solvent 440 

bath 426 

boiling point of 89, 84 

expansion of 88, 89 

density of 88. 89 

interstitial, of crystals 25 

maximum density of, 88, 89 

of ammonia 200 

crystallization 15, 20, 26-28 

specific weight of, 88, 89 

vapor 95 

volume of, 88, 89, 503, 504, 504 
one grain of, 12 

weight of, 88, 89, 503, 504, 505 
Water-gas 173 
Water-glass 270 
Water-soluble substances 440 
Waters 480 

Waves of heat and light 85, 98 
Wax 385 

Weather and health 98 
Wedge 57 
Weighty 10, 61,62 

absolute 10, 61, 62 

apparent 10, 61, 62 



Weight, molecular 145-148 

specific 10-12 

true 10, 61, 62 

relation to volume 503, 504, 506 
Weights and measures 503-505 

apothecaries' 504 

British 504, 505 

metric 503 

Imperial 505 
Wet processes 130, 131 

way j 30, 131 
White light 100 

precipitate 209, 241 
Wild cherry bark 357 
Wind 81 
Wines 487 
Wood spirit 281 
Woods 331 
Woody fibre 3 '4 
Work, rate of, 54 
Worm 455 
Wormseed American 368 

german 363 

levantic 363 
Woulf 's bottles 458 
Yellow jasmine 347 
Zero absolute 80 

thermometric 78 
Zinc and compounds 204 

group 202 
Zinziber 354 
















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